Polymers functionalized with imine compounds containing a protected thiol group

ABSTRACT

A method for preparing a functionalized polymer, the method comprising the steps of: (i) polymerizing monomer to form a reactive polymer, and (ii) reacting the reactive polymer with an imine compound containing a protected thiol group

This application claims the benefit of U.S. Provisional Application Ser.No. 62/196,534, filed on Jul. 24, 2015, which is incorporated herein byreference.

FIELD OF THE INVENTION

One or more embodiments of the present invention relate to polymersfunctionalized with imine compounds containing a protected thiol group.

BACKGROUND OF THE INVENTION

In the art of manufacturing tires, it is desirable to employ rubbervulcanizates that demonstrate reduced hysteresis, i.e., less loss ofmechanical energy to heat. For example, rubber vulcanizates that showreduced hysteresis are advantageously employed in tire components, suchas sidewalls and treads, to yield tires having desirably low rollingresistance. The hysteresis of a rubber vulcanizate is often attributedto the free polymer chain ends within a crosslinked rubber network, aswell as the dissociation of filler agglomerates.

Functionalized polymers have been employed to reduce the hysteresis ofrubber vulcanizates. The functional group of the functionalized polymermay reduce the number of free polymer chain ends via interaction withfiller particles. Also, the functional group may reduce filleragglomeration. Nevertheless, whether a particular functional groupimparted to a polymer can reduce hysteresis is often unpredictable.

Functionalized polymers may be prepared by post-polymerization treatmentof reactive polymers with certain functionalizing agents. However,whether a reactive polymer can be functionalized by treatment with aparticular functionalizing agent can be unpredictable. For example,functionalizing agents that work for one type of polymer do notnecessarily work for another type of polymer, and vice versa.

Lanthanide-based catalyst systems are known to be useful forpolymerizing conjugated diene monomer to form polydienes having a highcontent of cis-1,4-linkage. The resulting cis-1,4-polydienes may displaypseudo-living characteristics in that, upon completion of thepolymerization, some of the polymer chains possess reactive ends thatcan react with certain functionalizing agents to yield functionalizedcis-1,4-polydienes.

The cis-1,4-polydienes produced with lanthanide-based catalyst systemstypically have a linear backbone, which is believed to provide bettertensile properties, higher abrasion resistance, lower hysteresis, andbetter fatigue resistance as compared to the cis-1,4-polydienes preparedwith other catalyst systems such as titanium-, cobalt-, and nickel-basedcatalyst systems. Therefore, the cis-1,4-polydienes made withlanthanide-based catalysts are particularly suitable for use in tirecomponents such as sidewalls and treads.

Anionic initiators are known to be useful for the polymerization ofconjugated diene monomer to form polydienes having a combination of1,2-, cis-1,4- and trans-1,4-linkages. Anionic initiators are alsouseful for the copolymerization of conjugated diene monomer withvinyl-substituted aromatic compounds. The polymers prepared with anionicinitiators may display living characteristics in that, upon completionof the polymerization, the polymer chains possess living ends that arecapable of reacting with additional monomer for further chain growth orreacting with certain functionalizing agents to give functionalizedpolymers.

Because functionalized polymers are advantageous, especially in themanufacture of tires, there exists a need to develop new functionalizedpolymers that give reduced hysteresis.

SUMMARY OF THE INVENTION

One or more embodiments of the present invention provides a method forpreparing a functionalized polymer, the method comprising the steps of:(i) polymerizing monomer to form a reactive polymer, and (ii) reactingthe reactive polymer with an imine compound containing a protected thiolgroup.

Other embodiments of the present invention provide a method forpreparing a functionalized polymer, the method comprising the steps of:(i) polymerizing conjugated diene monomer, and optionally monomercopolymerizable therewith, to form a polymer having a reactive chainend; and (ii) reacting the reactive chain end of the polymer with animine compound containing a protected thiol group.

Other embodiments of the present invention provide a functionalizedpolymer prepared by the steps of (i) polymerizing conjugated dienemonomer, and optionally monomer copolymerizable therewith, to form apolymer having a reactive chain end; and (ii) reacting the reactivechain end of the polymer with an imine compound containing a protectedthiol group.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graphical plot of cold-flow gauge (mm at 8 min) versusMooney viscosity (ML 1+4 at 100° C.) for functionalizedcis-1,4-polybutadiene prepared according to one or more embodiments ofthe present invention as compared to unfunctionalizedcis-1,4-polybutadiene.

FIG. 2 is a graphical plot of hysteresis loss (tan 6) versus Mooneyviscosity (ML 1+4 at 130° C.) for vulcanizates prepared fromfunctionalized cis-1,4-polybutadiene prepared according to one or moreembodiments of the present invention as compared to vulcanizatesprepared from unfunctionalized cis-1,4-polybutadiene.

FIG. 3 is a graphical plot of hysteresis loss (tan 6) versus Mooneyviscosity (ML 1+4 at 130° C.) for vulcanizates prepared fromfunctionalized cis-1,4-polybutadiene as compared to vulcanizatesprepared from unfunctionalized cis-1,4-polybutadiene.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

According to one or more embodiments of the present invention, areactive polymer is prepared by polymerizing conjugated diene monomerand optionally monomer copolymerizable therewith, and this reactivepolymer is then functionalized by reaction with an imine compoundcontaining a protected thiol group. The resultant functionalizedpolymers can be used in the manufacture of tire components. In one ormore embodiments, the resultant functionalized polymers provide tirecomponents that exhibit advantageously low hysteresis.

Examples of conjugated diene monomer include 1,3-butadiene, isoprene,1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene,2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene,4-methyl-1,3-pentadiene, and 2,4-hexadiene. Mixtures of two or moreconjugated dienes may also be utilized in copolymerization.

Examples of monomer copolymerizable with conjugated diene monomerinclude vinyl-substituted aromatic compounds such as styrene,p-methylstyrene, α-methylstyrene, and vinylnaphthalene.

In one or more embodiments, the reactive polymer is prepared bycoordination polymerization, wherein monomer is polymerized by using acoordination catalyst system. The key mechanistic features ofcoordination polymerization have been discussed in books (e.g., Kuran,W., Principles of Coordination Polymerization; John Wiley & Sons: NewYork, 2001) and review articles (e.g., Mulhaupt, R., MacromolecularChemistry and Physics 2003, volume 204, pages 289-327). Coordinationcatalysts are believed to initiate the polymerization of monomer by amechanism that involves the coordination or complexation of monomer toan active metal center prior to the insertion of monomer into a growingpolymer chain. An advantageous feature of coordination catalysts istheir ability to provide stereochemical control of polymerizations andthereby produce stereoregular polymers. As is known in the art, thereare numerous methods for creating coordination catalysts, but allmethods eventually generate an active intermediate that is capable ofcoordinating with monomer and inserting monomer into a covalent bondbetween an active metal center and a growing polymer chain. Thecoordination polymerization of conjugated dienes is believed to proceedvia π-allyl complexes as intermediates. Coordination catalysts can beone-, two-, three- or multi-component systems. In one or moreembodiments, a coordination catalyst may be formed by combining a heavymetal compound (e.g., a transition metal compound or alanthanide-containing compound), an alkylating agent (e.g., anorganoaluminum compound), and optionally other co-catalyst components(e.g., a Lewis acid or a Lewis base). In one or more embodiments, theheavy metal compound may be referred to as a coordinating metalcompound.

Various procedures can be used to prepare coordination catalysts. In oneor more embodiments, a coordination catalyst may be formed in situ byseparately adding the catalyst components to the monomer to bepolymerized in either a stepwise or simultaneous manner. In otherembodiments, a coordination catalyst may be preformed. That is, thecatalyst components are pre-mixed outside the polymerization systemeither in the absence of any monomer or in the presence of a smallamount of monomer. The resulting preformed catalyst composition may beaged, if desired, and then added to the monomer that is to bepolymerized.

Useful coordination catalyst systems include lanthanide-based catalystsystems. These catalyst systems may advantageously producecis-1,4-polydienes that, prior to quenching, have reactive chain endsand may be referred to as pseudo-living polymers. While othercoordination catalyst systems may also be employed, lanthanide-basedcatalysts have been found to be particularly advantageous, andtherefore, without limiting the scope of the present invention, will bediscussed in greater detail.

Practice of the present invention is not necessarily limited by theselection of any particular lanthanide-based catalyst system. In one ormore embodiments, the catalyst systems employed include (a) alanthanide-containing compound, (b) an alkylating agent, and (c) ahalogen source. In other embodiments, a compound containing anon-coordinating anion or a non-coordinating anion precursor can beemployed in lieu of a halogen source. In these or other embodiments,other organometallic compounds, Lewis bases, and/or catalyst modifierscan be employed in addition to the ingredients or components set forthabove. For example, in one embodiment, a nickel-containing compound canbe employed as a molecular weight regulator as disclosed in U.S. Pat.No. 6,699,813, which is incorporated herein by reference.

As mentioned above, the lanthanide-based catalyst systems employed inthe present invention can include a lanthanide-containing compound.Lanthanide-containing compounds useful in the present invention arethose compounds that include at least one atom of lanthanum, neodymium,cerium, praseodymium, promethium, samarium, europium, gadolinium,terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, anddidymium. In one embodiment, these compounds can include neodymium,lanthanum, samarium, or didymium. As used herein, the term “didymium”shall denote a commercial mixture of rare-earth elements obtained frommonazite sand. In addition, the lanthanide-containing compounds usefulin the present invention can be in the form of elemental lanthanide.

The lanthanide atom in the lanthanide-containing compounds can be invarious oxidation states including, but not limited to, the 0, +2, +3,and +4 oxidation states. In one embodiment, a trivalentlanthanide-containing compound, where the lanthanide atom is in the +3oxidation state, can be employed. Suitable lanthanide-containingcompounds include, but are not limited to, lanthanide carboxylates,lanthanide organophosphates, lanthanide organophosphonates, lanthanideorganophosphinates, lanthanide carbamates, lanthanide dithiocarbamates,lanthanide xanthates, lanthanide β-diketonates, lanthanide alkoxides oraryloxides, lanthanide halides, lanthanide pseudo-halides, lanthanideoxyhalides, and organolanthanide compounds.

In one or more embodiments, the lanthanide-containing compounds can besoluble in hydrocarbon solvents such as aromatic hydrocarbons, aliphatichydrocarbons, or cycloaliphatic hydrocarbons. Hydrocarbon-insolublelanthanide-containing compounds, however, may also be useful in thepresent invention, as they can be suspended in the polymerization mediumto form the catalytically active species.

For ease of illustration, further discussion of usefullanthanide-containing compounds will focus on neodymium compounds,although those skilled in the art will be able to select similarcompounds that are based upon other lanthanide metals.

Suitable neodymium carboxylates include, but are not limited to,neodymium formate, neodymium acetate, neodymium acrylate, neodymiummethacrylate, neodymium valerate, neodymium gluconate, neodymiumcitrate, neodymium fumarate, neodymium lactate, neodymium maleate,neodymium oxalate, neodymium 2-ethylhexanoate, neodymium neodecanoate(a.k.a., neodymium versatate), neodymium naphthenate, neodymiumstearate, neodymium oleate, neodymium benzoate, and neodymiumpicolinate.

Suitable neodymium organophosphates include, but are not limited to,neodymium dibutyl phosphate, neodymium dipentyl phosphate, neodymiumdihexyl phosphate, neodymium diheptyl phosphate, neodymium dioctylphosphate, neodymium bis(1-methylheptyl) phosphate, neodymiumbis(2-ethylhexyl) phosphate, neodymium didecyl phosphate, neodymiumdidodecyl phosphate, neodymium dioctadecyl phosphate, neodymium dioleylphosphate, neodymium diphenyl phosphate, neodymium bis(p-nonylphenyl)phosphate, neodymium butyl (2-ethylhexyl) phosphate, neodymium(1-methylheptyl) (2-ethylhexyl) phosphate, and neodymium (2-ethylhexyl)(p-nonylphenyl) phosphate.

Suitable neodymium organophosphonates include, but are not limited to,neodymium butyl phosphonate, neodymium pentyl phosphonate, neodymiumhexyl phosphonate, neodymium heptyl phosphonate, neodymium octylphosphonate, neodymium (1-methylheptyl) phosphonate, neodymium(2-ethylhexyl) phosphonate, neodymium decyl phosphonate, neodymiumdodecyl phosphonate, neodymium octadecyl phosphonate, neodymium oleylphosphonate, neodymium phenyl phosphonate, neodymium (p-nonylphenyl)phosphonate, neodymium butyl butylphosphonate, neodymium pentylpentylphosphonate, neodymium hexyl hexylphosphonate, neodymium heptylheptylphosphonate, neodymium octyl octylphosphonate, neodymium(1-methylheptyl) (1-methylheptyl)phosphonate, neodymium (2-ethylhexyl)(2-ethylhexyl)phosphonate, neodymium decyl decylphosphonate, neodymiumdodecyl dodecylphosphonate, neodymium octadecyl octadecylphosphonate,neodymium oleyl oleylphosphonate, neodymium phenyl phenylphosphonate,neodymium (p-nonylphenyl) (p-nonylphenyl)phosphonate, neodymium butyl(2-ethylhexyl)phosphonate, neodymium (2-ethylhexyl) butylphosphonate,neodymium (1-methylheptyl) (2-ethylhexyl)phosphonate, neodymium(2-ethylhexyl) (1-methylheptyl)phosphonate, neodymium (2-ethylhexyl)(p-nonylphenyl)phosphonate, and neodymium (p-nonylphenyl)(2-ethylhexyl)phosphonate.

Suitable neodymium organophosphinates include, but are not limited to,neodymium butylphosphinate, neodymium pentylphosphinate, neodymiumhexylphosphinate, neodymium heptylphosphinate, neodymiumoctylphosphinate, neodymium (1-methylheptyl)phosphinate, neodymium(2-ethylhexyl) phosphinate, neodymium decylphosphinate, neodymiumdodecylphosphinate, neodymium octadecylphosphinate, neodymiumoleylphosphinate, neodymium phenylphosphinate, neodymium(p-nonylphenyl)phosphinate, neodymium dibutylphosphinate, neodymiumdipentylphosphinate, neodymium dihexylphosphinate, neodymiumdiheptylphosphinate, neodymium dioctylphosphinate, neodymiumbis(1-methylheptyl)phosphinate, neodymium bis(2-ethylhexyl)phosphinate,neodymium didecylphosphinate, neodymium didodecylphosphinate, neodymiumdioctadecylphosphinate, neodymium dioleylphosphinate, neodymiumdiphenylphosphinate, neodymium bis(p-nonylphenyl) phosphinate, neodymiumbutyl (2-ethylhexyl) phosphinate, neodymium (1-methylheptyl)(2-ethylhexyl)phosphinate, and neodymium (2-ethylhexyl)(p-nonylphenyl)phosphinate.

Suitable neodymium carbamates include, but are not limited to, neodymiumdimethylcarbamate, neodymium diethylcarbamate, neodymiumdiisopropylcarbamate, neodymium dibutylcarbamate, and neodymiumdibenzylcarbamate.

Suitable neodymium dithiocarbamates include, but are not limited to,neodymium dimethyldithiocarbamate, neodymium diethyldithiocarbamate,neodymium diisopropyldithiocarbamate, neodymium dibutyldithiocarbamate,and neodymium dibenzyldithiocarbamate.

Suitable neodymium xanthates include, but are not limited to, neodymiummethylxanthate, neodymium ethylxanthate, neodymium isopropylxanthate,neodymium butylxanthate, and neodymium benzylxanthate.

Suitable neodymium β-diketonates include, but are not limited to,neodymium acetylacetonate, neodymium trifluoroacetylacetonate, neodymiumhexafluoroacetylacetonate, neodymium benzoylacetonate, and neodymium2,2,6,6-tetramethyl-3,5-heptanedionate.

Suitable neodymium alkoxides or aryloxides include, but are not limitedto, neodymium methoxide, neodymium ethoxide, neodymium isopropoxide,neodymium 2-ethylhexoxide, neodymium phenoxide, neodymiumnonylphenoxide, and neodymium naphthoxide.

Suitable neodymium halides include, but are not limited to, neodymiumfluoride, neodymium chloride, neodymium bromide, and neodymium iodide.Suitable neodymium pseudo-halides include, but are not limited to,neodymium cyanide, neodymium cyanate, neodymium thiocyanate, neodymiumazide, and neodymium ferrocyanide. Suitable neodymium oxyhalidesinclude, but are not limited to, neodymium oxyfluoride, neodymiumoxychloride, and neodymium oxybromide. A Lewis base, such astetrahydrofuran (“THF”), may be employed as an aid for solubilizing thisclass of neodymium compounds in inert organic solvents. Where lanthanidehalides, lanthanide oxyhalides, or other lanthanide-containing compoundscontaining a halogen atom are employed, the lanthanide-containingcompound may optionally also provide all or part of the halogen sourcein the lanthanide-based catalyst system.

As used herein, the term organolanthanide compound refers to anylanthanide-containing compound containing at least one lanthanide-carbonbond. These compounds are predominantly, though not exclusively, thosecontaining cyclopentadienyl (“Cp”), substituted cyclopentadienyl, allyl,and substituted allyl ligands. Suitable organolanthanide compoundsinclude, but are not limited to, Cp₃Ln, Cp₂LnR, Cp₂LnCl, CpLnCl₂,CpLn(cyclooctatetraene), (C₅Me₅)₂LnR, LnR₃, Ln(allyl)₃, andLn(allyl)₂Cl, where Ln represents a lanthanide atom, and R represents ahydrocarbyl group. In one or more embodiments, hydrocarbyl groups usefulin the present invention may contain heteroatoms such as, for example,nitrogen, oxygen, boron, silicon, sulfur, and phosphorus atoms.

As mentioned above, the lanthanide-based catalyst systems employed inthe present invention can include an alkylating agent. In one or moreembodiments, alkylating agents, which may also be referred to ashydrocarbylating agents, include organometallic compounds that cantransfer one or more hydrocarbyl groups to another metal. Generally,these agents include organometallic compounds of electropositive metalssuch as Groups 1, 2, and 3 metals (Groups IA, IIA, and IIIA metals).Alkylating agents useful in the present invention include, but are notlimited to, organoaluminum and organomagnesium compounds. As usedherein, the term organoaluminum compound refers to any aluminum compoundcontaining at least one aluminum-carbon bond. In one or moreembodiments, organoaluminum compounds that are soluble in a hydrocarbonsolvent can be employed. As used herein, the term organomagnesiumcompound refers to any magnesium compound that contains at least onemagnesium-carbon bond. In one or more embodiments, organomagnesiumcompounds that are soluble in a hydrocarbon can be employed. As will bedescribed in more detail below, several species of suitable alkylatingagents can be in the form of a halide. Where the alkylating agentincludes a halogen atom, the alkylating agent may also serve as all orpart of the halogen source in the above-mentioned catalyst system.

In one or more embodiments, organoaluminum compounds that can beutilized in the lanthanide-based catalyst system include thoserepresented by the general formula AlR_(n)X_(3-n), where each Rindependently can be a monovalent organic group that is attached to thealuminum atom via a carbon atom, where each X independently can be ahydrogen atom, a halogen atom, a carboxylate group, an alkoxide group,or an aryloxide group, and where n can be an integer in the range offrom 1 to 3. In one or more embodiments, each R independently can be ahydrocarbyl group such as, for example, alkyl, cycloalkyl, substitutedcycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl,substituted aryl, aralkyl, alkaryl, allyl, and alkynyl groups, with eachgroup containing in the range of from 1 carbon atom, or the appropriateminimum number of carbon atoms to form the group, up to about 20 carbonatoms. These hydrocarbyl groups may contain heteroatoms including, butnot limited to, nitrogen, oxygen, boron, silicon, sulfur, and phosphorusatoms.

Types of the organoaluminum compounds that are represented by thegeneral formula AlR_(n)X_(3-n) include, but are not limited to,trihydrocarbylaluminum, dihydrocarbylaluminum hydride,hydrocarbylaluminum dihydride, dihydrocarbylaluminum carboxylate,hydrocarbylaluminum bis(carboxylate), dihydrocarbylaluminum alkoxide,hydrocarbylaluminum dialkoxide, dihydrocarbylaluminum halide,hydrocarbylaluminum dihalide, dihydrocarbylaluminum aryloxide, andhydrocarbylaluminum diaryloxide compounds. In one embodiment, thealkylating agent can comprise trihydrocarbylaluminum,dihydrocarbylaluminum hydride, and/or hydrocarbylaluminum dihydridecompounds. In one embodiment, when the alkylating agent includes anorganoaluminum hydride compound, the above-mentioned halogen source canbe provided by a tin halide, as disclosed in U.S. Pat. No. 7,008,899,which is incorporated herein by reference in its entirety.

Suitable trihydrocarbylaluminum compounds include, but are not limitedto, trimethylaluminum, triethylaluminum, triisobutylaluminum,tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum,tri-t-butylaluminum, tri-n-pentylaluminum, trineopentylaluminum,tri-n-hexylaluminum, tri-n-octylaluminum, tris(2-ethylhexyl)aluminum,tricyclohexylaluminum, tris(1-methylcyclopentyl)aluminum,triphenylaluminum, tri-p-tolylaluminum,tris(2,6-dimethylphenyl)aluminum, tribenzylaluminum,diethylphenylaluminum, diethyl-p-tolylaluminum, diethylbenzylaluminum,ethyldiphenylaluminum, ethyldi-p-tolylaluminum, andethyldibenzylaluminum.

Suitable dihydrocarbylaluminum hydride compounds include, but are notlimited to, diethylaluminum hydride, di-n-propylaluminum hydride,diisopropylaluminum hydride, di-n-butylaluminum hydride,diisobutylaluminum hydride, di-n-octylaluminum hydride, diphenylaluminumhydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride,phenylethylaluminum hydride, phenyl-n-propylaluminum hydride,phenylisopropylaluminum hydride, phenyl-n-butylaluminum hydride,phenylisobutylaluminum hydride, phenyl-n-octylaluminum hydride,p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride,p-tolylisopropylaluminum hydride, p-tolyl-n-butylaluminum hydride,p-tolylisobutylaluminum hydride, p-tolyl-n-octylaluminum hydride,benzylethylaluminum hydride, benzyl-n-propylaluminum hydride,benzylisopropylaluminum hydride, benzyl-n-butylaluminum hydride,benzylisobutylaluminum hydride, and benzyl-n-octylaluminum hydride.

Suitable hydrocarbylaluminum dihydrides include, but are not limited to,ethylaluminum dihydride, n-propylaluminum dihydride, isopropylaluminumdihydride, n-butylaluminum dihydride, is obutylaluminum dihydride, andn-octylaluminum dihydride.

Suitable dihydrocarbylaluminum halide compounds include, but are notlimited to, diethylaluminum chloride, di-n-propylaluminum chloride,diisopropylaluminum chloride, di-n-butylaluminum chloride,diisobutylaluminum chloride, di-n-octylaluminum chloride,diphenylaluminum chloride, di-p-tolylaluminum chloride, dibenzylaluminumchloride, phenylethylaluminum chloride, phenyl-n-propylaluminumchloride, phenylisopropylaluminum chloride, phenyl-n-butylaluminumchloride, phenylisobutylaluminum chloride, phenyl-n-octylaluminumchloride, p-tolylethylaluminum chloride, p-tolyl-n-propylaluminumchloride, p-tolylisopropylaluminum chloride, p-tolyl-n-butylaluminumchloride, p-tolylisobutylaluminum chloride, p-tolyl-n-octylaluminumchloride, benzylethylaluminum chloride, benzyl-n-propylaluminumchloride, benzylisopropylaluminum chloride, benzyl-n-butylaluminumchloride, benzylisobutylaluminum chloride, and benzyl-n-octylaluminumchloride.

Suitable hydrocarbylaluminum dihalide compounds include, but are notlimited to, ethylaluminum dichloride, n-propylaluminum dichloride,isopropylaluminum dichloride, n-butylaluminum dichloride,isobutylaluminum dichloride, and n-octylaluminum dichloride.

Other organoaluminum compounds useful as alkylating agents that may berepresented by the general formula AlR_(n)X_(3-n) include, but are notlimited to, dimethylaluminum hexanoate, diethylaluminum octoate,diisobutylaluminum 2-ethylhexanoate, dimethylaluminum neodecanoate,diethylaluminum stearate, diisobutylaluminum oleate, methylaluminumbis(hexanoate), ethylaluminum bis(octoate), isobutylaluminumbis(2-ethylhexanoate), methylaluminum bis(neodecanoate), ethylaluminumbis(stearate), isobutylaluminum bis(oleate), dimethylaluminum methoxide,diethylaluminum methoxide, diisobutylaluminum methoxide,dimethylaluminum ethoxide, diethylaluminum ethoxide, diisobutylaluminumethoxide, dimethylaluminum phenoxide, diethylaluminum phenoxide,diisobutylaluminum phenoxide, methylaluminum dimethoxide, ethylaluminumdimethoxide, isobutylaluminum dimethoxide, methylaluminum diethoxide,ethylaluminum diethoxide, isobutylaluminum diethoxide, methylaluminumdiphenoxide, ethylaluminum diphenoxide, and isobutylaluminumdiphenoxide.

Another class of organoaluminum compounds suitable for use as analkylating agent in the lanthanide-based catalyst system isaluminoxanes. Aluminoxanes can comprise oligomeric linear aluminoxanes,which can be represented by the general formula:

and oligomeric cyclic aluminoxanes, which can be represented by thegeneral formula:

where x can be an integer in the range of from 1 to about 100, or about10 to about 50; y can be an integer in the range of from 2 to about 100,or about 3 to about 20; and where each R independently can be amonovalent organic group that is attached to the aluminum atom via acarbon atom. In one embodiment, each R independently can be ahydrocarbyl group including, but not limited to, alkyl, cycloalkyl,substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl,aryl, substituted aryl, aralkyl, alkaryl, allyl, and alkynyl groups,with each group containing in the range of from 1 carbon atom, or theappropriate minimum number of carbon atoms to form the group, up toabout 20 carbon atoms. These hydrocarbyl groups may also containheteroatoms including, but not limited to, nitrogen, oxygen, boron,silicon, sulfur, and phosphorus atoms. It should be noted that thenumber of moles of the aluminoxane as used in this application refers tothe number of moles of the aluminum atoms rather than the number ofmoles of the oligomeric aluminoxane molecules. This convention iscommonly employed in the art of catalyst systems utilizing aluminoxanes.

Aluminoxanes can be prepared by reacting trihydrocarbylaluminumcompounds with water. This reaction can be performed according to knownmethods, such as, for example, (1) a method in which thetrihydrocarbylaluminum compound is dissolved in an organic solvent andthen contacted with water, (2) a method in which thetrihydrocarbylaluminum compound is reacted with water of crystallizationcontained in, for example, metal salts, or water adsorbed in inorganicor organic compounds, or (3) a method in which thetrihydrocarbylaluminum compound is reacted with water in the presence ofthe monomer or monomer solution that is to be polymerized.

Suitable aluminoxane compounds include, but are not limited to,methylaluminoxane (“MAO”), modified methylaluminoxane (“MMAO”),ethylaluminoxane, n-propylaluminoxane, isopropylaluminoxane,butylaluminoxane, isobutylaluminoxane, n-pentylaluminoxane,neopentylaluminoxane, n-hexylaluminoxane, n-octylaluminoxane,2-ethylhexylaluminoxane, cyclohexylaluminoxane,1-methylcyclopentylaluminoxane, phenylaluminoxane, and2,6-dimethylphenylaluminoxane. Modified methylaluminoxane can be formedby substituting about 20 to 80 percent of the methyl groups ofmethylaluminoxane with C₂ to C₁₂ hydrocarbyl groups, preferably withisobutyl groups, by using techniques known to those skilled in the art.

In one or more embodiments, aluminoxanes can be used alone or incombination with other organoaluminum compounds. In one embodiment,methylaluminoxane and at least one other organoaluminum compound (e.g.,AlR_(n)X_(3-n)), such as diisobutyl aluminum hydride, can be employed incombination. U.S. Publication No. 2008/0182954, which is incorporatedherein by reference in its entirety, provides other examples wherealuminoxanes and organoaluminum compounds can be employed incombination.

As mentioned above, alkylating agents useful in the lanthanide-basedcatalyst system can include organomagnesium compounds. In one or moreembodiments, organomagnesium compounds that can be utilized includethose represented by the general formula MgR₂, where each Rindependently can be a monovalent organic group that is attached to themagnesium atom via a carbon atom. In one or more embodiments, each Rindependently can be a hydrocarbyl group including, but not limited to,alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl,substituted cycloalkenyl, aryl, allyl, substituted aryl, aralkyl,alkaryl, and alkynyl groups, with each group containing in the range offrom 1 carbon atom, or the appropriate minimum number of carbon atoms toform the group, up to about 20 carbon atoms. These hydrocarbyl groupsmay also contain heteroatoms including, but not limited to, nitrogen,oxygen, silicon, sulfur, and phosphorus atoms.

Suitable organomagnesium compounds that may be represented by thegeneral formula MgR₂ include, but are not limited to, diethylmagnesium,di-n-propylmagnesium, diisopropylmagnesium, dibutylmagnesium,dihexylmagnesium, diphenylmagnesium, and dibenzylmagnesium.

Another class of organomagnesium compounds that can be utilized as analkylating agent may be represented by the general formula RMgX, where Rcan be a monovalent organic group that is attached to the magnesium atomvia a carbon atom, and X can be a hydrogen atom, a halogen atom, acarboxylate group, an alkoxide group, or an aryloxide group. Where thealkylating agent is an organomagnesium compound that includes a halogenatom, the organomagnesium compound can serve as both the alkylatingagent and at least a portion of the halogen source in the catalystsystems. In one or more embodiments, R can be a hydrocarbyl groupincluding, but not limited to, alkyl, cycloalkyl, substitutedcycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl,allyl, substituted aryl, aralkyl, alkaryl, and alkynyl groups, with eachgroup containing in the range of from 1 carbon atom, or the appropriateminimum number of carbon atoms to form the group, up to about 20 carbonatoms. These hydrocarbyl groups may also contain heteroatoms including,but not limited to, nitrogen, oxygen, boron, silicon, sulfur, andphosphorus atoms. In one embodiment, X can be a carboxylate group, analkoxide group, or an aryloxide group, with each group containing in therange of from 1 to about 20 carbon atoms.

Types of organomagnesium compounds that may be represented by thegeneral formula RMgX include, but are not limited to,hydrocarbylmagnesium hydride, hydrocarbylmagnesium halide,hydrocarbylmagnesium carboxylate, hydrocarbylmagnesium alkoxide, andhydrocarbylmagnesium aryloxide.

Suitable organomagnesium compounds that may be represented by thegeneral formula RMgX include, but are not limited to, methylmagnesiumhydride, ethylmagnesium hydride, butylmagnesium hydride, hexylmagnesiumhydride, phenylmagnesium hydride, benzylmagnesium hydride,methylmagnesium chloride, ethylmagnesium chloride, butylmagnesiumchloride, hexylmagnesium chloride, phenylmagnesium chloride,benzylmagnesium chloride, methylmagnesium bromide, ethylmagnesiumbromide, butylmagnesium bromide, hexylmagnesium bromide, phenylmagnesiumbromide, benzylmagnesium bromide, methylmagnesium hexanoate,ethylmagnesium hexanoate, butylmagnesium hexanoate, hexylmagnesiumhexanoate, phenylmagnesium hexanoate, benzylmagnesium hexanoate,methylmagnesium ethoxide, ethylmagnesium ethoxide, butylmagnesiumethoxide, hexylmagnesium ethoxide, phenylmagnesium ethoxide,benzylmagnesium ethoxide, methylmagnesium phenoxide, ethylmagnesiumphenoxide, butylmagnesium phenoxide, hexylmagnesium phenoxide,phenylmagnesium phenoxide, and benzylmagnesium phenoxide.

As mentioned above, the lanthanide-based catalyst systems employed inthe present invention can include a halogen source. As used herein, theterm halogen source refers to any substance including at least onehalogen atom. In one or more embodiments, at least a portion of thehalogen source can be provided by either of the above-describedlanthanide-containing compound and/or the above-described alkylatingagent, when those compounds contain at least one halogen atom. In otherwords, the lanthanide-containing compound can serve as both thelanthanide-containing compound and at least a portion of the halogensource. Similarly, the alkylating agent can serve as both the alkylatingagent and at least a portion of the halogen source.

In another embodiment, at least a portion of the halogen source can bepresent in the catalyst systems in the form of a separate and distincthalogen-containing compound. Various compounds, or mixtures thereof,that contain one or more halogen atoms can be employed as the halogensource. Examples of halogen atoms include, but are not limited to,fluorine, chlorine, bromine, and iodine. A combination of two or morehalogen atoms can also be utilized. Halogen-containing compounds thatare soluble in a hydrocarbon solvent are suitable for use in the presentinvention. Hydrocarbon-insoluble halogen-containing compounds, however,can be suspended in a polymerization system to form the catalyticallyactive species, and are therefore also useful.

Useful types of halogen-containing compounds that can be employedinclude, but are not limited to, elemental halogens, mixed halogens,hydrogen halides, organic halides, inorganic halides, metallic halides,and organometallic halides.

Suitable elemental halogens include, but are not limited to, fluorine,chlorine, bromine, and iodine. Some specific examples of suitable mixedhalogens include iodine monochloride, iodine monobromide, iodinetrichloride, and iodine pentafluoride.

Suitable hydrogen halides include, but are not limited to, hydrogenfluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide.

Suitable organic halides include, but are not limited to, t-butylchloride, t-butyl bromide, allyl chloride, allyl bromide, benzylchloride, benzyl bromide, chloro-di-phenylmethane,bromo-di-phenylmethane, triphenylmethyl chloride, triphenylmethylbromide, benzylidene chloride, benzylidene bromide,methyltrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane,diphenyldichlorosilane, trimethylchlorosilane, benzoyl chloride, benzoylbromide, propionyl chloride, propionyl bromide, methyl chloroformate,and methyl bromoformate.

Suitable inorganic halides include, but are not limited to, phosphorustrichloride, phosphorus tribromide, phosphorus pentachloride, phosphorusoxychloride, phosphorus oxybromide, boron trifluoride, borontrichloride, boron tribromide, silicon tetrafluoride, silicontetrachloride, silicon tetrabromide, silicon tetraiodide, arsenictrichloride, arsenic tribromide, arsenic triiodide, seleniumtetrachloride, selenium tetrabromide, tellurium tetrachloride, telluriumtetrabromide, and tellurium tetraiodide.

Suitable metallic halides include, but are not limited to, tintetrachloride, tin tetrabromide, aluminum trichloride, aluminumtribromide, antimony trichloride, antimony pentachloride, antimonytribromide, aluminum triiodide, aluminum trifluoride, galliumtrichloride, gallium tribromide, gallium triiodide, gallium trifluoride,indium trichloride, indium tribromide, indium triiodide, indiumtrifluoride, titanium tetrachloride, titanium tetrabromide, titaniumtetraiodide, zinc dichloride, zinc dibromide, zinc diiodide, and zincdifluoride.

Suitable organometallic halides include, but are not limited to,dimethylaluminum chloride, diethylaluminum chloride, dimethylaluminumbromide, diethylaluminum bromide, dimethylaluminum fluoride,diethylaluminum fluoride, methylaluminum dichloride, ethylaluminumdichloride, methylaluminum dibromide, ethylaluminum dibromide,methylaluminum difluoride, ethylaluminum difluoride, methylaluminumsesquichloride, ethylaluminum sesquichloride, isobutylaluminumsesquichloride, methylmagnesium chloride, methylmagnesium bromide,methylmagnesium iodide, ethylmagnesium chloride, ethylmagnesium bromide,butylmagnesium chloride, butylmagnesium bromide, phenylmagnesiumchloride, phenylmagnesium bromide, benzylmagnesium chloride,trimethyltin chloride, trimethyltin bromide, triethyltin chloride,triethyltin bromide, di-t-butyltin dichloride, di-t-butyltin dibromide,dibutyltin dichloride, dibutyltin dibromide, tributyltin chloride, andtributyltin bromide.

In one or more embodiments, the lanthanide-based catalyst systems cancomprise a compound containing a non-coordinating anion or anon-coordinating anion precursor. In one or more embodiments, a compoundcontaining a non-coordinating anion, or a non-coordinating anionprecursor can be employed in lieu of the above-described halogen source.A non-coordinating anion is a sterically bulky anion that does not formcoordinate bonds with, for example, the active center of a catalystsystem due to stearic hindrance. Non-coordinating anions useful in thepresent invention include, but are not limited to, tetraarylborateanions and fluorinated tetraarylborate anions. Compounds containing anon-coordinating anion can also contain a counter cation, such as acarbonium, ammonium, or phosphonium cation. Exemplary counter cationsinclude, but are not limited to, triarylcarbonium cations andN,N-dialkylanilinium cations. Examples of compounds containing anon-coordinating anion and a counter cation include, but are not limitedto, triphenylcarbonium tetrakis(pentafluorophenyl)borate,N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,triphenylcarbonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, andN,N-dimethylanilinium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate.

A non-coordinating anion precursor can also be used in this embodiment.A non-coordinating anion precursor is a compound that is able to form anon-coordinating anion under reaction conditions. Usefulnon-coordinating anion precursors include, but are not limited to,triarylboron compounds, BR₃, where R is a strong electron-withdrawingaryl group, such as a pentafluorophenyl or3,5-bis(trifluoromethyl)phenyl group.

The lanthanide-based catalyst composition used in this invention may beformed by combining or mixing the foregoing catalyst ingredients.Although one or more active catalyst species are believed to result fromthe combination of the lanthanide-based catalyst ingredients, the degreeof interaction or reaction between the various catalyst ingredients orcomponents is not known with any great degree of certainty. Therefore,the term “catalyst composition” has been employed to encompass a simplemixture of the ingredients, a complex of the various ingredients that iscaused by physical or chemical forces of attraction, a chemical reactionproduct of the ingredients, or a combination of the foregoing.

The foregoing lanthanide-based catalyst composition may have highcatalytic activity for polymerizing conjugated dienes intocis-1,4-polydienes over a wide range of catalyst concentrations andcatalyst ingredient ratios. Several factors may impact the optimumconcentration of any one of the catalyst ingredients. For example,because the catalyst ingredients may interact to form an active species,the optimum concentration for any one catalyst ingredient may bedependent upon the concentrations of the other catalyst ingredients.

In one or more embodiments, the molar ratio of the alkylating agent tothe lanthanide-containing compound (alkylating agent/Ln) can be variedfrom about 1:1 to about 1,000:1, in other embodiments from about 2:1 toabout 500:1, and in other embodiments from about 5:1 to about 200:1.

In those embodiments where both an aluminoxane and at least one otherorganoaluminum agent are employed as alkylating agents, the molar ratioof the aluminoxane to the lanthanide-containing compound(aluminoxane/Ln) can be varied from 5:1 to about 1,000:1, in otherembodiments from about 10:1 to about 700:1, and in other embodimentsfrom about 20:1 to about 500:1; and the molar ratio of the at least oneother organoaluminum compound to the lanthanide-containing compound(Al/Ln) can be varied from about 1:1 to about 200:1, in otherembodiments from about 2:1 to about 150:1, and in other embodiments fromabout 5:1 to about 100:1.

The molar ratio of the halogen-containing compound to thelanthanide-containing compound is best described in terms of the ratioof the moles of halogen atoms in the halogen source to the moles oflanthanide atoms in the lanthanide-containing compound (halogen/Ln). Inone or more embodiments, the halogen/Ln molar ratio can be varied fromabout 0.5:1 to about 20:1, in other embodiments from about 1:1 to about10:1, and in other embodiments from about 2:1 to about 6:1.

In yet another embodiment, the molar ratio of the non-coordinating anionor non-coordinating anion precursor to the lanthanide-containingcompound (An/Ln) may be from about 0.5:1 to about 20:1, in otherembodiments from about 0.75:1 to about 10:1, and in other embodimentsfrom about 1:1 to about 6:1.

The lanthanide-based catalyst composition can be formed by variousmethods.

In one embodiment, the lanthanide-based catalyst composition may beformed in situ by adding the catalyst ingredients to a solutioncontaining monomer and solvent, or to bulk monomer, in either a stepwiseor simultaneous manner. In one embodiment, the alkylating agent can beadded first, followed by the lanthanide-containing compound, and thenfollowed by the halogen source or by the compound containing anon-coordinating anion or the non-coordinating anion precursor.

In another embodiment, the lanthanide-based catalyst composition may bepreformed. That is, the catalyst ingredients are pre-mixed outside thepolymerization system either in the absence of any monomer or in thepresence of a small amount of at least one conjugated diene monomer atan appropriate temperature, which may be from about −20° C. to about 80°C. The amount of conjugated diene monomer that may be used forpreforming the catalyst can range from about 1 to about 500 moles, inother embodiments from about 5 to about 250 moles, and in otherembodiments from about 10 to about 100 moles per mole of thelanthanide-containing compound. The resulting catalyst composition maybe aged, if desired, prior to being added to the monomer that is to bepolymerized.

In yet another embodiment, the lanthanide-based catalyst composition maybe formed by using a two-stage procedure. The first stage may involvecombining the alkylating agent with the lanthanide-containing compoundeither in the absence of any monomer or in the presence of a smallamount of at least one conjugated diene monomer at an appropriatetemperature, which may be from about −20° C. to about 80° C. The amountof monomer employed in the first stage may be similar to that set forthabove for preforming the catalyst. In the second stage, the mixtureformed in the first stage and the halogen source, non-coordinatinganion, or non-coordinating anion precursor can be charged in either astepwise or simultaneous manner to the monomer that is to bepolymerized.

In one or more embodiments, the reactive polymer is prepared by anionicpolymerization, wherein monomer is polymerized by using an anionicinitiator. The key mechanistic features of anionic polymerization havebeen described in books (e.g., Hsieh, H. L.; Quirk, R. P. AnionicPolymerization: Principles and Practical Applications; Marcel Dekker:New York, 1996) and review articles (e.g., Hadjichristidis, N.;Pitsikalis, M.; Pispas, S.; Iatrou, H.; Chem. Rev. 2001, 101(12),3747-3792). Anionic initiators may advantageously produce livingpolymers that, prior to quenching, are capable of reacting withadditional monomer for further chain growth or reacting with certainfunctionalizing agents to give functionalized polymers.

The practice of this invention is not limited by the selection of anyparticular anionic initiators. In one or more embodiments, the anionicinitiator employed is a functional initiator that imparts a functionalgroup at the head of the polymer chain (i.e., the location from whichthe polymer chain is started). In particular embodiments, the functionalgroup includes one or more heteroatoms (e.g., nitrogen, oxygen, boron,silicon, sulfur, tin, and phosphorus atoms) or heterocyclic groups. Incertain embodiments, the functional group reduces the 50° C. hysteresisloss of carbon-black filled vulcanizates prepared from polymerscontaining the functional group as compared to similar carbon-blackfilled vulcanizates prepared from polymer that does not include thefunctional group.

Exemplary anionic initiators include organolithium compounds. In one ormore embodiments, organolithium compounds may include heteroatoms. Inthese or other embodiments, organolithium compounds may include one ormore heterocyclic groups.

Types of organolithium compounds include alkyllithium, aryllithiumcompounds, and cycloalkyllithium compounds. Specific examples oforganolithium compounds include ethyllithium, n-propyllithium,isopropyllithium, n-butyllithium, sec-butyllithium, t-butyllithium,n-amyllithium, isoamyllithium, and phenyllithium.

Other anionic initiators include alkylmagnesium halide compounds such asbutylmagnesium bromide and phenylmagnesium bromide. Still other anionicinitiators include organosodium compounds such as phenylsodium and2,4,6-trimethylphenylsodium. Also contemplated are those anionicinitiators that give rise to di-living polymers, wherein both ends of apolymer chain are living. Examples of such initiators include dilithioinitiators such as those prepared by reacting 1,3-diisopropenylbenzenewith sec-butyllithium. These and related difunctional initiators aredisclosed in U.S. Pat. No. 3,652,516, which is incorporated herein byreference. Radical anionic initiators may also be employed, includingthose described in U.S. Pat. No. 5,552,483, which is incorporated hereinby reference.

In particular embodiments, the organolithium compounds include a cyclicamine-containing compound such as lithiohexamethyleneimine. These andrelated useful initiators are disclosed in the U.S. Pat. Nos. 5,332,810,5,329,005, 5,578,542, 5,393,721, 5,698,646, 5,491,230, 5,521,309,5,496,940, 5,574,109, and 5,786,441, which are incorporated herein byreference. In other embodiments, the organolithium compounds includelithiated alkylthioacetals such as 2-lithio-2-methyl-1,3-dithiane. Theseand related useful initiators are disclosed in U.S. Publ. Nos.2006/0030657, 2006/0264590, and 2006/0264589, which are incorporatedherein by reference. In still other embodiments, the organolithiumcompounds include alkoxysilyl-containing initiators, such as lithiatedt-butyldimethylpropoxysilane. These and related useful initiators aredisclosed in U.S. Publ. No. 2006/0241241, which is incorporated hereinby reference.

In one or more embodiments, the anionic initiator employed istrialkyltinlithium compound such as tri-n-butyltinlithium. These andrelated useful initiators are disclosed in U.S. Pat. Nos. 3,426,006 and5,268,439, which are incorporated herein by reference.

When elastomeric copolymers containing conjugated diene monomer andvinyl-substituted aromatic monomer are prepared by anionicpolymerization, the conjugated diene monomer and vinyl-substitutedaromatic monomer may be used at a weight ratio of 95:5 to 50:50, or inother embodiments, 90:10 to 65:35. In order to promote the randomizationof comonomers in copolymerization and to control the microstructure(such as 1,2-linkage of conjugated diene monomer) of the polymer, arandomizer, which is typically a polar coordinator, may be employedalong with the anionic initiator.

Compounds useful as randomizers include those having an oxygen ornitrogen heteroatom and a non-bonded pair of electrons. Exemplary typesof randomizers include linear and cyclic oligomeric oxolanyl alkanes;dialkyl ethers of mono and oligo alkylene glycols (also known as glymeethers); crown ethers; tertiary amines; linear THF oligomers; alkalimetal alkoxides; and alkali metal sulfonates. Linear and cyclicoligomeric oxolanyl alkanes are described in U.S. Pat. No. 4,429,091,which is incorporated herein by reference. Specific examples ofrandomizers include 2,2-bis(2′-tetrahydrofuryl)propane,1,2-dimethoxyethane, N,N,N′,N′-tetramethylethylenediamine (TMEDA),tetrahydrofuran (THF), 1,2-dipiperidylethane, dipiperidylmethane,hexamethylphosphoramide, N,N′-dimethylpiperazine, diazabicyclooctane,dimethyl ether, diethyl ether, tri-n-butylamine, potassium t-amylate,potassium 4-dodecylsulfonate, and mixtures thereof.

The amount of randomizer to be employed may depend on various factorssuch as the desired microstructure of the polymer, the ratio of monomerto comonomer, the polymerization temperature, as well as the nature ofthe specific randomizer employed. In one or more embodiments, the amountof randomizer employed may range between 0.05 and 100 moles per mole ofthe anionic initiator.

The anionic initiator and the randomizer can be introduced to thepolymerization system by various methods. In one or more embodiments,the anionic initiator and the randomizer may be added separately to themonomer to be polymerized in either a stepwise or simultaneous manner.In other embodiments, the anionic initiator and the randomizer may bepre-mixed outside the polymerization system either in the absence of anymonomer or in the presence of a small amount of monomer, and theresulting mixture may be aged, if desired, and then added to the monomerthat is to be polymerized.

In one or more embodiments, regardless of whether a coordinationcatalyst or an anionic initiator is used to prepare the reactivepolymer, a solvent may be employed as a carrier to either dissolve orsuspend the catalyst or initiator in order to facilitate the delivery ofthe catalyst or initiator to the polymerization system. In otherembodiments, monomer can be used as the carrier. In yet otherembodiments, the catalyst or initiator can be used in their neat statewithout any solvent.

In one or more embodiments, suitable solvents include those organiccompounds that will not undergo polymerization or incorporation intopropagating polymer chains during the polymerization of monomer in thepresence of the catalyst or initiator. In one or more embodiments, theseorganic species are liquid at ambient temperature and pressure. In oneor more embodiments, these organic solvents are inert to the catalyst orinitiator. Exemplary organic solvents include hydrocarbons with a low orrelatively low boiling point such as aromatic hydrocarbons, aliphatichydrocarbons, and cycloaliphatic hydrocarbons. Non-limiting examples ofaromatic hydrocarbons include benzene, toluene, xylenes, ethylbenzene,diethylbenzene, and mesitylene. Non-limiting examples of aliphatichydrocarbons include n-pentane, n-hexane, n-heptane, n-octane, n-nonane,n-decane, isopentane, isohexanes, isopentanes, isooctanes,2,2-dimethylbutane, petroleum ether, kerosene, and petroleum spirits.And, non-limiting examples of cycloaliphatic hydrocarbons includecyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane.Mixtures of the above hydrocarbons may also be used. As is known in theart, aliphatic and cycloaliphatic hydrocarbons may be desirably employedfor environmental reasons. The low-boiling hydrocarbon solvents aretypically separated from the polymer upon completion of thepolymerization.

Other examples of organic solvents include high-boiling hydrocarbons ofhigh molecular weights, including hydrocarbon oils that are commonlyused to oil-extend polymers. Examples of these oils include paraffinicoils, aromatic oils, naphthenic oils, vegetable oils other than castoroils, and low PCA oils including MES, TDAE, SRAE, heavy naphthenic oils.Since these hydrocarbons are non-volatile, they typically do not requireseparation and remain incorporated in the polymer.

The production of the reactive polymer according to this invention canbe accomplished by polymerizing conjugated diene monomer, optionallytogether with monomer copolymerizable with conjugated diene monomer, inthe presence of a catalytically effective amount of the catalyst orinitiator. The introduction of the catalyst or initiator, the conjugateddiene monomer, optionally the comonomer, and any solvent, if employed,forms a polymerization mixture in which the reactive polymer is formed.The amount of the catalyst or initiator to be employed may depend on theinterplay of various factors such as the type of catalyst or initiatoremployed, the purity of the ingredients, the polymerization temperature,the polymerization rate and conversion desired, the molecular weightdesired, and many other factors. Accordingly, a specific catalyst orinitiator amount cannot be definitively set forth except to say thatcatalytically effective amounts of the catalyst or initiator may beused.

In one or more embodiments, the amount of the coordinating metalcompound (e.g., a lanthanide-containing compound) used can be variedfrom about 0.001 to about 2 mmol, in other embodiments from about 0.005to about 1 mmol, and in still other embodiments from about 0.01 to about0.2 mmol per 100 gram of monomer.

In other embodiments, where an anionic initiator (e.g., an alkyllithiumcompound) is employed, the initiator loading may be varied from about0.05 to about 100 mmol, in other embodiments from about 0.1 to about 50mmol, and in still other embodiments from about 0.2 to about 5 mmol per100 gram of monomer.

In one or more embodiments, the polymerization may be carried out in apolymerization system that includes a substantial amount of solvent. Inone embodiment, a solution polymerization system may be employed inwhich both the monomer to be polymerized and the polymer formed aresoluble in the solvent. In another embodiment, a precipitationpolymerization system may be employed by choosing a solvent in which thepolymer formed is insoluble. In both cases, an amount of solvent inaddition to the amount of solvent that may be used in preparing thecatalyst or initiator is usually added to the polymerization system. Theadditional solvent may be the same as or different from the solvent usedin preparing the catalyst or initiator. Exemplary solvents have been setforth above. In one or more embodiments, the solvent content of thepolymerization mixture may be more than 20% by weight, in otherembodiments more than 50% by weight, and in still other embodiments morethan 80% by weight based on the total weight of the polymerizationmixture.

In other embodiments, the polymerization system employed may begenerally considered a bulk polymerization system that includessubstantially no solvent or a minimal amount of solvent. Those skilledin the art will appreciate the benefits of bulk polymerization processes(i.e., processes where monomer acts as the solvent), and therefore thepolymerization system includes less solvent than will deleteriouslyimpact the benefits sought by conducting bulk polymerization. In one ormore embodiments, the solvent content of the polymerization mixture maybe less than about 20% by weight, in other embodiments less than about10% by weight, and in still other embodiments less than about 5% byweight based on the total weight of the polymerization mixture. Inanother embodiment, the polymerization mixture contains no solventsother than those that are inherent to the raw materials employed. Instill another embodiment, the polymerization mixture is substantiallydevoid of solvent, which refers to the absence of that amount of solventthat would otherwise have an appreciable impact on the polymerizationprocess. Polymerization systems that are substantially devoid of solventmay be referred to as including substantially no solvent. In particularembodiments, the polymerization mixture is devoid of solvent.

The polymerization may be conducted in any conventional polymerizationvessels known in the art. In one or more embodiments, solutionpolymerization can be conducted in a conventional stirred-tank reactor.In other embodiments, bulk polymerization can be conducted in aconventional stirred-tank reactor, especially if the monomer conversionis less than about 60%. In still other embodiments, especially where themonomer conversion in a bulk polymerization process is higher than about60%, which typically results in a highly viscous cement, the bulkpolymerization may be conducted in an elongated reactor in which theviscous cement under polymerization is driven to move by piston, orsubstantially by piston. For example, extruders in which the cement ispushed along by a self-cleaning single-screw or double-screw agitatorare suitable for this purpose. Examples of useful bulk polymerizationprocesses are disclosed in U.S. Pat. No. 7,351,776, which isincorporated herein by reference.

In one or more embodiments, all of the ingredients used for thepolymerization can be combined within a single vessel (e.g., aconventional stirred-tank reactor), and all steps of the polymerizationprocess can be conducted within this vessel. In other embodiments, twoor more of the ingredients can be pre-combined in one vessel and thentransferred to another vessel where the polymerization of monomer (or atleast a major portion thereof) may be conducted.

The polymerization can be carried out as a batch process, a continuousprocess, or a semi-continuous process. In the semi-continuous process,the monomer is intermittently charged as needed to replace that monomeralready polymerized. In one or more embodiments, the conditions underwhich the polymerization proceeds may be controlled to maintain thetemperature of the polymerization mixture within a range from about −10°C. to about 200° C., in other embodiments from about 0° C. to about 150°C., and in other embodiments from about 20° C. to about 100° C. In oneor more embodiments, the heat of polymerization may be removed byexternal cooling by a thermally controlled reactor jacket, internalcooling by evaporation and condensation of the monomer through the useof a reflux condenser connected to the reactor, or a combination of thetwo methods. Also, the polymerization conditions may be controlled toconduct the polymerization under a pressure of from about 0.1 atmosphereto about 50 atmospheres, in other embodiments from about 0.5 atmosphereto about 20 atmosphere, and in other embodiments from about 1 atmosphereto about 10 atmospheres. In one or more embodiments, the pressures atwhich the polymerization may be carried out include those that ensurethat the majority of the monomer is in the liquid phase. In these orother embodiments, the polymerization mixture may be maintained underanaerobic conditions.

Regardless of whether the polymerization is catalyzed or initiated by acoordination catalyst (e.g., a lanthanide-based catalyst) or an anionicinitiator (e.g., an alkyllithium initiator), some or all of theresulting polymer chains may possess reactive chain ends before thepolymerization mixture is quenched. Thus, reference to a reactivepolymer refers to a polymer having a reactive chain end deriving from asynthesis of the polymer by using a coordination catalyst or an anionicinitiator. As noted above, the reactive polymer prepared with acoordination catalyst (e.g., a lanthanide-based catalyst) may bereferred to as a pseudo-living polymer, and the reactive polymerprepared with an anionic initiator (e.g., an alkyllithium initiator) maybe referred to as a living polymer. In one or more embodiments, apolymerization mixture including reactive polymer may be referred to asan active polymerization mixture. The percentage of polymer chainspossessing a reactive end depends on various factors such as the type ofcatalyst or initiator, the type of monomer, the purity of theingredients, the polymerization temperature, the monomer conversion, andmany other factors. In one or more embodiments, at least about 20% ofthe polymer chains possess a reactive end, in other embodiments at leastabout 50% of the polymer chains possess a reactive end, and in stillother embodiments at least about 80% of the polymer chains possess areactive end. In any event, the reactive polymer can be reacted with animine compound containing a protected thiol group.

In one or more embodiments, imine compounds containing a protected thiolgroup include those compounds that contain at least one imine group andat least one protected thiol group. In one or more embodiments, the atleast one imine group may be directly tethered to the at least oneprotected thiol group via a bond. In other embodiments, the at least oneimine group may be indirectly tethered to the at least one protectedthiol group via a divalent organic group.

In one or more embodiments, protected thiol groups include those sulfurcontaining groups that are formed or derived by replacing the hydrogenatom of the parent thiol group (i.e. —SH) with other substituentsincluding monovalent organic group such as hydrocarbyl or silyl groups.In one or more embodiments, the imine group of the imine compoundcontaining a protected thiol group is directly or indirectly tethered tothe sulfur atom in the protected thiol group. In these or otherembodiments, the imine group is not connected to the protected thiolthrough the protecting group.

In one or more embodiments, where the hydrogen atom of the parent thiolgroup is replaced with a hydrocarbon group, the protected thiol groupmay be referred to as a hydrocarbylthio group. In one or moreembodiments, where the hydrogen atom of the parent thiol group isreplaced with a silyl group, the protected thiol group may be referredto as a silylthio group.

In one or more embodiments, the protected thiol group may be ahydrolyzable thiol group. In these or other embodiments, thehydrolyzable thiol group may be defined by the following formula:

—S—R⁴

where R⁴ is a hydrolyzable group.

In one or more embodiments, the monovalent organic groups of the iminecompound containing a protected thiol group may be hydrocarbyl groups,which include, but are not limited to, alkyl, cycloalkyl, alkenyl,cycloalkenyl, aryl, allyl, aralkyl, alkaryl, or alkynyl groups.Hydrocarbyl groups also include substituted hydrocarbyl groups, whichrefer to hydrocarbyl groups in which one or more hydrogen atoms havebeen replaced by a substituent such as a hydrocarbyl, hydrocarbyloxy,silyl, or silyloxy group. In one or more embodiments, these groups mayinclude from one, or the appropriate minimum number of carbon atoms toform the group, to about 20 carbon atoms. These groups may also containheteroatoms such as, but not limited to, nitrogen, boron, oxygen,silicon, sulfur, tin, and phosphorus atoms.

In one or more embodiments, the hydrolyzable groups of the iminecompound containing a protected thiol group include those groups orsubstituents that are relatively stable and therefore remain chemicallybonded to the sulfur atom in non-aqueous environments or environmentsthat are devoid or substantially devoid of water. However, once exposedto water, moisture, or materials containing water or moisture, thehydrolyzable groups or substituents are hydrolyzed and thereby cleavedfrom the sulfur atom. As a result, the hydrolyzable groups are replacedby a hydrogen atom. A catalyst may be used to cleave the hydrolyzablegroups from the sulfur atom. Suitable catalysts for this purpose includetetrabutylammonium fluoride, strong acids such as hydrochloric acid, andLewis acids such as titanium tetrachloride.

Exemplary hydrolyzable groups include silyl groups or substituted silylgroups. Types of silyl groups and substituted silyl groups include, butare not limited to, trihydrocarbylsilyl, trisilyloxysilyl,trihydrocarbyloxysilyl, trisilylsilyl, dihydrocarbylhydrosilyl,dihydrocarbyl(silyloxy)silyl, dihydrocarbyl(silyl)silyl,dihydrocarbyl(hydrocarbyloxy)silyl, hydrocarbyldihydrosilyl,hydrocarbyl(disilyloxy)silyl, hydrocarbyl(disilyl)silyl, andhydrocarbyl(dihydrocarbyloxy)silyl groups. For example, types of silylgroups may include trialkylsilyl, dialkylhydrosilyl,dialkyl(silyloxy)silyl, dialkyl(silyl)silyl, tricycloalkylsilyl,dicycloalkylhydrosilyl, dicycloalkyl(silyloxy)silyl,dicycloalkyl(silyl)silyl, trialkenylsilyl, dialkenylhydrosilyl,dialkenyl(silyloxy)silyl, dialkenyl(silyl)silyl, tricycloalkenylsilyl,dicycloalkenylhydrosilyl, dicycloalkenyl(silyloxy)silyl,dicycloalkenyl(silyl)silyl, triarylsilyl, diarylhydrosilyl,diaryl(silyloxy)silyl, diaryl(silyl)silyl, triallylsilyl,diallylhydrosilyl, diallyl(silyloxy)silyl, diallyl(silyl)silyl,triaralkylsilyl, diaralkylhydrosilyl, diaralkyl(silyloxy)silyl,diaralkyl(silyl)silyl, trialkarylsilyl, dialkarylhydrosilyl,dialkaryl(silyloxy)silyl, dialkaryl(silyl)silyl, trialkynylsilyl,dialkynylhydrosilyl, dialkynyl(silyloxy)silyl, dialkynyl(silyl)silyl,tris(trialkylsilyloxy)silyl, tris(triarylsilyloxy)silyl,tris(tricycloalkylsilyloxy)silyl, tris(trialkoxysilyloxy)silyl,tris(triaryloxysilyloxy)silyl, or tris(tricycloalkyloxysilyloxy)silylgroups. Substituted silyl groups include silyl groups in which one ormore hydrogen atoms have been replaced by a substituent such as ahydrocarbyl, hydrocarbyloxy, silyl, or siloxy group. In one or moreembodiments, these groups may include from one, or the appropriateminimum number of carbon atoms to form the group, to about 20 carbonatoms. These groups may also contain heteroatoms such as, but notlimited to, nitrogen, boron, oxygen, silicon, sulfur, tin, andphosphorus atoms.

As those skilled in the art appreciate, imines include aldimine groupsand ketamine groups. In one or more embodiments, the imine group may bedefined by the following formula:

where each R is individual a hydrogen atom, a monovalent organic group,or combine to make a divalent organic group. In one or more embodiments,where each R is a monovalent organic group, the imine group may bereferred to as a ketimine group. In one or more embodiments, where one Ris a hydrogen atom and the other R is a monovalent organic group, theimine group may be referred to as an aldimine group.

In one or more embodiments, where the protected thiol group of the iminecompound containing a protected thiol is hydrolyzable thiol group, theimine compound containing a hydrolyzable may be defined by the formulaI:

where R¹ is a hydrogen atom or a monovalent organic group, R² is a bondor a divalent organic group, R³ is a monovalent organic group, and R⁴ isa hydrolyzable group, or where R¹ and R² join to form a trivalentorganic group, or where R¹ and R³ join to form a divalent organic group.

In one or more embodiments, where the protected thiol group of the iminecompound containing a protected thiol is hydrolyzable thiol group, theimine compound containing a hydrolyzable may be defined by the formulaII:

where R⁴ is a hydrolyzable group, R⁵ and R⁶ are each independently ahydrogen atom or a monovalent organic group, and R² is a bond or adivalent organic group, or where R⁵ and R⁶ join to form a divalentorganic group, or where R² and R⁵ join to form a trivalent organicgroup.

In one or more embodiments, where R¹ and R² of formula I join to form atrivalent organic group, an imine compound containing a hydrolyzablethiol group may be defined by the formula III:

where R³ is a monovalent organic group, R⁴ is a hydrolyzable group, andR⁷ is a trivalent organic group.

In one or more embodiments, where R⁵ and R⁶ of formula II join to form adivalent organic group, an imine compound containing a hydrolyzablethiol group may be defined by the formula IV:

where R² is a bond or a divalent organic group, R⁴ is a hydrolyzablegroup, and R⁸ is a divalent organic group.

In one or more embodiments, where R¹ and R³ of formula I join to form adivalent organic group, an imine compound containing a hydrolyzablethiol group may be defined by the formula V:

where R² is a bond or a divalent organic group, R⁴ is a hydrolyzablegroup, and R¹⁰ is a divalent organic group.

In one or more embodiments, where the R⁴ of formula I is a silyl group,an imine compound containing a hydrolyzable thiol group may be definedby the formula VI:

where R¹ is a hydrogen atom or a monovalent organic group, R² is a bondor a divalent organic group, R³ is a monovalent organic group, and eachR⁹ is individually a hydrogen atom or a monovalent organic group, orwhere R¹ and R² join to form a trivalent organic group, or where R¹ andR³ join to form a divalent organic group.

In one or more embodiments, where the R⁴ of formula II is a silyl group,an imine compound containing a hydrolyzable thiol group may be definedby the formula VII:

where R² is a bond or a divalent organic group, R⁵ and R⁶ are eachindependently a hydrogen atom or a monovalent organic group, and each R⁹is individually a hydrogen atom or a monovalent organic group, or whereR⁵ and R⁶ join to form a divalent organic group, or where R² and R⁵ jointo form a trivalent organic group.

In one or more embodiments, where the R⁴ of formula III is a silylgroup, an imine compound containing a hydrolyzable thiol group may bedefined by the formula VIII:

where R³ is a monovalent organic group, R⁷ is a trivalent organic group,and each R⁹ is individually a hydrogen atom or a monovalent organicgroup.

In one or more embodiments, where the R⁴ of formula IV is a silyl group,an imine compound containing a hydrolyzable thiol group may be definedby the formula IX:

where R² is a bond or a divalent organic group, R⁸ is a divalent organicgroup, and each R⁹ is individually a hydrogen atom or a monovalentorganic group.

In one or more embodiments, where the R⁴ of formula V is a silyl group,an imine compound containing a hydrolyzable thiol group may be definedby the formula X:

where R² is a bond or a divalent organic group, each R⁹ is individuallya hydrogen atom or a monovalent organic group, and R¹⁰ is a divalentorganic group.

In one or more embodiments, the divalent organic groups of the iminecompound containing a protected thiol group may be hydrocarbylenegroups, which include, but are not limited to, alkylene, cycloalkylene,alkenylene, cycloalkenylene, alkynylene, cycloalkynylene, or arylenegroups. Hydrocarbylene groups include substituted hydrocarbylene groups,which refer to hydrocarbylene groups in which one or more hydrogen atomshave been replaced by a substituent such as a hydrocarbyl,hydrocarbyloxy, silyl, or silyloxy group. In one or more embodiments,these groups may include from one, or the appropriate minimum number ofcarbon atoms to form the group, to about 20 carbon atoms. These groupsmay also contain one or more heteroatoms such as, but not limited to,nitrogen, oxygen, boron, silicon, sulfur, tin, and phosphorus atoms.

In one or more embodiments, the monovalent, divalent, and/or trivalentgroups of the imine compound containing a protected thiol group maycontain one or more imine groups or protected thiol groups. For example,a protected thiol group may be pendantly attached to R¹, R², or R³ offormula I. In these embodiments, the imine compound containing aprotected thiol group may contain two or more protected thiol groups orimine groups.

In one or more embodiments, where the imine compound containing aprotected thiol group is defined by the formula I and the hydrolyzablegroup of the hydrolyzable thiol group is a silyl group, the iminecompound containing a hydrolyzable thiol group may be referred to as anN-(silylthiohydrocarbylidene)hydrocarbylamine. In one or moreembodiments, where the R² of formula I is an arylene group and R³ is anaryl group, the N-(silylthiohydrocarbylidene)hydrocarbylamine may bereferred to as an N-[α-(silylthioaryl)hydrocarbylidene]arylamine. In oneor more embodiments, where the R² of formula I is an alkylene group andR³ is an alkyl group, the N-(silylthiohydrocarbylidene)hydrocarbylaminemay be referred to as an N-(silylthioalkylidene)alkylamine. In one ormore embodiments, where the R² of formula I is an arylene group and R³is an alkyl group, the N-(silylthiohydrocarbylidene)hydrocarbylamine maybe referred to as an N-[α-(silylthioaryl)hydrocarbylidene]alkylamine. Inone or more embodiments, where the R² of formula I is an alkylene groupand R³ is an aryl group, theN-(silylthiohydrocarbylidene)hydrocarbylamine may be referred to as anN-(silylthioalkylidene)arylamine.

In one or more embodiments, where the imine compound containing aprotected thiol group is defined by the formula II and the hydrolyzablegroup of the hydrolyzable thiol group is a silyl group, the iminecompound containing a hydrolyzable thiol group may be referred to as anN-hydrocarbylidene(silylthiohydrocarbyl)amine. In one or moreembodiments, where the R² of formula II is an arylene group and eitherR⁴ or R⁵ is an aryl group, theN-hydrocarbylidene(silylthiohydrocarbyl)amine may be referred to as anN-(α-arylhydrocarbylidene)(silylthioaryl)amine. In one or moreembodiments, where the R² of formula II is an alkylene group, and whereR⁴ and R⁵ are each independently a hydrogen atom or an alkyl group, theN-hydrocarbylidene(silylthiohydrocarbyl)amine may be referred to as anN-alkylidene(silylthioalkyl)amine. In one or more embodiments, where theR² of formula II is an alkylene group and either R⁴ or R⁵ is an arylgroup, the N-hydrocarbylidene(silylthiohydrocarbyl)amine may be referredto as an N-(α-arylhydrocarbylidene) (silylthioalkyl)amine. In one ormore embodiments, where the R² of formula II is an arylene group, andwhere R⁴ and R⁵ are each independently a hydrogen atom or an alkylgroup, the N-hydrocarbylidene(silylyhiohydrocarbyl)amine may be referredto as an N-alkylidene(silylthioaryl)amine.

In one or more embodiments, where the imine compound containing aprotected thiol group is defined by the formula III and the hydrolyzablegroup of the hydrolyzable thiol group is a silyl group, the iminecompound containing a protected thiol group may be referred to as anN-(silylthiocyclohydrocarbylidene)hydrocarbylamine. In one or moreembodiments, where the R³ of formula III is an alkyl group, theN-(silylthiocyclohydrocarbylidene)hydrocarbylamine may be referred to asan N-(silylthiocyclohydrocarbylidene)alkylamine. In one or moreembodiments, where the R³ of formula III is an aryl group, theN-(silylthiocyclohydrocarbylidene)hydrocarbylamine may be referred to asan N-(silylthiocyclohydrocarbylidene)arylamine.

In one or more embodiments, where the imine compound containing aprotected thiol group is defined by the formula IV and the hydrolyzablegroup of the hydrolyzable thiol group is a silyl group, the iminecompound containing a protected thiol group may be referred to as anN-cyclohydrocarbylidene(silylthiohydrocarbyl)amine. In one or moreembodiments, where the R² of formula IV is a alkylene group, theN-cyclohydrocarbylidene(silylthiohydrocarbyl)amine may be referred to asan N-cyclohydrocarbylidene(silylthioalkyl)amine. In one or moreembodiments, where the R² of formula IV is an arylene group, theN-cyclohydrocarbylidene(silylthiohydrocarbyl)amine may be referred to asan N-cyclohydrocarbylidene(silylthioaryl)amine.

Representative examples ofN-[α-(silylthioaryl)hydrocarbylidene]arylamines include the cis andtrans isomers of N-[2-(trimethylsilylthio)benzylidene]aniline,N-[3-(trimethylsilylthio)benzylidene]aniline,N-[4-(trimethylsilylthio)benzylidene]aniline,N-[2-(trimethylsilylthio)benzylidene]-2-methylaniline,N-[3-(trimethylsilylthio)benzylidene]-2-methylaniline,N-[4-(trimethylsilylthio)benzylidene]-2-methylaniline,N-[2-(trimethylsilylthio)benzylidene]-3-methylaniline,N-[3-(trimethylsilylthio)benzylidene]-3-methylaniline,N-[4-(trimethylsilylthio)benzylidene]-3-methylaniline,N-[2-(trimethylsilylthio)benzylidene]-4-methylaniline,N-[3-(trimethylsilylthio)benzylidene]-4-methylaniline,N-[4-(trimethylsilylthio)benzylidene]-4-methylaniline,N-[2-(trimethylsilylthio)benzylidene]benzylamine,N-[3-(trimethylsilylthio)benzylidene]benzylamine, andN-[4-(trimethylsilylthio)benzylidene]benzylamine.

Representative examples of N-(silylthoalkylidene)alkylamines include thecis and trans isomers ofN-[2-(trimethylsilylthio)butylidene]-n-butylamine,N-[3-(trimethylsilylthio)butylidene]-n-butylamine,N-[4-(trimethylsilylthio)butylidene]-n-butylamine,N-[2-(trimethylsilylthio)butylidene]-n-pentylamine,N-[3-(trimethylsilylthio)butylidene]-n-pentylamine,N-[4-(trimethylsilylthio)butylidene]-n-pentylamine,N-[2-(trimethylsilylthio)butylidene]-n-hexylamine,N-[3-(trimethylsilylthio)butylidene]-n-hexylamine,N-[4-(trimethylsilylthio)butylidene]-n-hexylamine,N-[2-(trimethylsilylthio)butylidene]cyclopropylamine,N-[3-(trimethylsilylthio)butylidene]cyclopropylamine,N-[4-(trimethylsilylthio)butylidene]cyclopropylamine,N-[2-(trimethylsilylthio)butylidene]cyclopentylamine,N-[3-(trimethylsilylthio)butylidene]cyclopentylamine,N-[4-(trimethylsilylthio)butylidene]cyclopentylamine,N-[2-(trimethylsilylthio)butylidene]cyclohexylamine,N-[3-(trimethylsilylthio)butylidene]cyclohexylamine,N-[4-(trimethylsilylthio)butylidene]cyclohexylamine,N-[2-(trimethylsilylthio)butylidene]cycloheptylamine,N-[3-(trimethylsilylthio)butylidene]cycloheptylamine, andN-[4-(trimethylsilylthio)butylidene]cycloheptylamine.

Representative examples ofN-[α-(silylthioaryl)hydrocarbylidene]alkylamines include the cis andtrans isomers N-[2-(trimethylsilylthio)benzylidene]-n-butylamine,N-[3-(trimethylsilylthio)benzylidene]-n-butylamine,N-[4-(trimethylsilylthio)benzylidene]-n-butylamine,N-[2-(trimethylsilylthio)benzylidene]-n-pentylamine,N-[3-(trimethylsilylthio)benzylidene]-n-pentylamine,N-[4-(trimethylsilylthio)benzylidene]-n-pentylamine,N-[2-(trimethylsilylthio)benzylidene]-n-hexylamine,N-[3-(trimethylsilylthio)benzylidene]-n-hexylamine,N-[4-(trimethylsilylthio)benzylidene]-n-hexylamine,N-[2-(trimethylsilylthio)benzylidene]cyclopropylamine,N-[3-(trimethylsilylthio)benzylidene]cyclopropylamine,N-[4-(trimethylsilylthio)benzylidene]cyclopropylamine,N-[2-(trimethylsilylthio)benzylidene]cyclopentylamine,N-[3-(trimethylsilylthio)benzylidene]cyclopentylamine,N-[4-(trimethylsilylthio)benzylidene]cyclopentylamine,N-[2-(trimethylsilylthio)benzylidene]cyclohexylamine,N-[3-(trimethylsilylthio)benzylidene]cyclohexylamine,N-[4-(trimethylsilylthio)benzylidene]cyclohexylamine,N-[2-(trimethylsilylthio)benzylidene]cycloheptylamine,N-[3-(trimethylsilylthio)benzylidene]cycloheptylamine, andN-[4-(trimethylsilylthio)benzylidene]cycloheptylamine.

Representative examples of N-(silylthioalkylidene)arylamines include thecis and trans isomers of N-[2-(trimethylsilylthio)butylidene]aniline,N-[3-(trimethylsilylthio)butylidene]aniline,N-[4-(trimethylsilylthio)butylidene]aniline,N-[2-(trimethylsilylthio)butylidene]-2-methylaniline,N-[3-(trimethylsilylthio)butylidene]-2-methylaniline,N-[4-(trimethylsilylthio)butylidene]-2-methylaniline,N-[2-(trimethylsilylthio)butylidene]-3-methylaniline,N-[3-(trimethylsilylthio)butylidene]-3-methylaniline,N-[4-(trimethylsilylthio)butylidene]-3-methylaniline,N-[2-(trimethylsilylthio)butylidene]-4-methylaniline,N-[3-(trimethylsilylthio)butylidene]-4-methylaniline, andN-[4-(trimethylsilylthio)butylidene]-4-methylaniline.

Representative examples of N-(α-arylhydrocarbylidene)(silylthioaryl)amines include the cis and trans isomers ofN-benzylidene-2-(trimethylsilylthio)aniline,N-benzylidene-3-(trimethylsilylthio)aniline,N-benzylidene-4-(trimethylsilylthio)aniline,N-benzylidene-1-(trimethylsilylthio)naphthalen-8-amine,N-benzylidene-2-(trimethylsilylthio)naphthalen-1-amine,N-(2-pyridylmethylidine)-2-(trimethylsilylthio)aniline,N-(2-pyridylmethylidine)-3-(trimethylsilylthio)aniline,N-(2-pyridylmethylidine)-4-(trimethylsilylthio)aniline,N-(2-pyridylmethylidine)-1-(trimethylsilylthio)naphthalen-8-amine,N-(2-pyridylmethylidine)-2-(trimethylsilylthio)naphthalen-1-amine,N-(2-methylbenzylidene)-2-(trimethylsilylthio)aniline,N-(2-methylbenzylidene)-3-(trimethylsilylthio)aniline,N-(2-methylbenzylidene)-4-(trimethylsilylthio)aniline,N-(2-methylbenzylidene)-1-(trimethylsilylthio)naphthalen-8-amine,N-(2-methylbenzylidene)-2-(trimethylsilylthio)naphthalen-1-amine,N-(3-methylbenzylidene)-2-(trimethylsilylthio)aniline,N-(3-methylbenzylidene)-3-(trimethylsilylthio)aniline,N-(3-methylbenzylidene)-4-(trimethylsilylthio)aniline,N-(3-methylbenzylidene)-1-(trimethylsilylthio)naphthalen-8-amine,N-(3-methylbenzylidene)-2-(trimethylsilylthio)naphthalen-1-amine,N-(4-methylbenzylidene)-2-(trimethylsilylthio)aniline,N-(4-methylbenzylidene)-3-(trimethylsilylthio)aniline,N-(4-methylbenzylidene)-4-(trimethylsilylthio)aniline,N-(4-methylbenzylidene)-1-(trimethylsilylthio)naphthalen-8-amine, andN-(4-methylbenzylidene)-2-(trimethylsilylthio)naphthalen-1-amine.

Representative examples of N-alkylidene(silylalkyl)amines include thecis and trans isomers of N-methylidene-2-(trimethylsilylthio)ethylamine,N-methylidene-2-(trimethylsilylthio)propylamine,N-methylidene-3-(trimethylsilylthio)propylamine,N-methylidene-2-(trimethylsilylthio)pentylamine,N-methylidene-3-(trimethylsilylthio)pentylamine,N-methylidene-4-(trimethylsilylthio)pentylamine,N-methylidene-5-(trimethylsilylthio)pentylamine,N-methylidene-4-(trimethylsilylthio)hexylamine,N-eth-2-ylidene-2-(trimethylsilylthio)ethylamine,N-eth-2-ylidene-2-(trimethylsilylthio)propylamine,N-eth-2-ylidene-3-(trimethylsilylthio)propylamine,N-eth-2-ylidene-2-(trimethylsilylthio)pentylamine,N-eth-2-ylidene-3-(trimethylsilylthio)pentylamine,N-eth-2-ylidene-4-(trimethylsilylthio)pentylamine,N-eth-2-ylidene-5-(trimethylsilylthio)pentylamine,N-eth-2-ylidene-4-(trimethylsilylthio)hexylamine,N-prop-3-ylidene-2-(trimethylsilylthio)ethylamine,N-prop-3-ylidene-2-(trimethylsilylthio)propylamine,N-prop-3-ylidene-3-(trimethylsilylthio)propylamine,N-prop-3-ylidene-2-(trimethylsilylthio)pentylamine,N-prop-3-ylidene-3-(trimethylsilylthio)pentylamine,N-prop-3-ylidene-4-(trimethylsilylthio)pentylamine,N-prop-3-ylidene-5-(trimethylsilylthio)pentylamine,N-prop-3-ylidene-4-(trimethylsilylthio)hexylamine,N-but-4-ylidene-2-(trimethylsilylthio)ethylamine,N-but-4-ylidene-2-(trimethylsilylthio)propylamine,N-but-4-ylidene-3-(trimethylsilylthio)propylamine,N-but-4-ylidene-2-(trimethylsilylthio)pentylamine,N-but-4-ylidene-3-(trimethylsilylthio)pentylamine,N-but-4-ylidene-4-(trimethylsilylthio)pentylamine,N-but-4-ylidene-5-(trimethylsilylthio)pentylamine,N-but-4-ylidene-4-(trimethylsilylthio)hexyl amine,N-pent-5-ylidene-2-(trimethylsilylthio)ethylamine,N-pent-5-ylidene-2-(trimethylsilylthio)propylamine,N-pent-5-ylidene-3-(trimethylsilylthio)propylamine,N-pent-5-ylidene-2-(trimethylsilylthio)pentylamine,N-pent-5-ylidene-3-(trimethylsilylthio)pentylamine,N-pent-5-ylidene-4-(trimethylsilylthio)pentylamine,N-pent-5-ylidene-5-(trimethylsilylthio)pentylamine, andN-pent-5-ylidene-4-(trimethylsilylthio)hexylamine.

Representative examples ofN-(α-arylhydrocarbylidene)(silylthioalkyl)amines include the cis andtrans isomers of N-benzylidene-2-(trimethylsilylthio)ethylamine,N-benzylidene-2-(trimethylsilylthio)propylamine,N-benzylidene-3-(trimethylsilylthio)propylamine,N-benzylidene-2-(trimethylsilylthio)pentylamine,N-benzylidene-3-(trimethylsilylthio)pentylamine,N-benzylidene-4-(trimethylsilylthio)pentylamine,N-benzylidene-5-(trimethylsilylthio)pentylamine,N-benzylidene-4-(trimethylsilylthio)hexylamine,N-(2-pyridylmethylidine)-2-(trimethylsilylthio)ethylamine,N-(2-pyridylmethylidine)-2-(trimethylsilylthio)propylamine,N-(2-pyridylmethylidine)-3-(trimethylsilylthio)propylamine,N-(2-pyridylmethylidine)-2-(trimethylsilylthio)pentylamine,N-(2-pyridylmethylidine)-3-(trimethylsilylthio)pentylamine,N-(2-pyridylmethylidine)-4-(trimethylsilylthio)pentylamine,N-(2-pyridylmethylidine)-5-(trimethylsilylthio)pentylamine,N-(2-pyridylmethylidine)-4-(trimethylsilylthio)hexylamine,N-(2-methylbenzylidene)-2-(trimethylsilylthio)ethylamine,N-(2-methylbenzylidene)-2-(trimethylsilylthio)propylamine,N-(2-methylbenzylidene)-3-(trimethylsilylthio)propylamine,N-(2-methylbenzylidene)-2-(trimethylsilylthio)pentylamine,N-(2-methylbenzylidene)-3-(trimethylsilylthio)pentylamine,N-(2-methylbenzylidene)-4-(trimethylsilylthio)pentylamine,N-(2-methylbenzylidene)-5-(trimethylsilylthio)pentylamine,N-(2-methylbenzylidene)-4-(trimethylsilylthio)hexylamine,N-(3-methylbenzylidene)-2-(trimethylsilylthio)ethylamine,N-(3-methylbenzylidene)-2-(trimethylsilylthio)propylamine,N-(3-methylbenzylidene)-3-(trimethylsilylthio)propylamine,N-(3-methylbenzylidene)-2-(trimethylsilylthio)pentylamine,N-(3-methylbenzylidene)-3-(trimethylsilylthio)pentylamine,N-(3-methylbenzylidene)-4-(trimethylsilylthio)pentylamine,N-(3-methylbenzylidene)-5-(trimethylsilylthio)pentylamine,N-(3-methylbenzylidene)-4-(trimethylsilylthio)hexylamine,N-(4-methylbenzylidene)-2-(trimethylsilylthio)ethylamine,N-(4-methylbenzylidene)-2-(trimethylsilylthio)propylamine,N-(4-methylbenzylidene)-3-(trimethylsilylthio)propylamine,N-(4-methylbenzylidene)-2-(trimethylsilylthio)pentylamine,N-(4-methylbenzylidene)-3-(trimethylsilylthio)pentylamine,N-(4-methylbenzylidene)-4-(trimethylsilylthio)pentylamine,N-(4-methylbenzylidene)-5-(trimethylsilylthio)pentylamine,N-(4-methylbenzylidene)-4-(trimethylsilylthio)hexylamine,

Representative examples of N-alkylidene(silylthioaryl)amines include thecis and trans isomers of N-methylidene-2-(trimethylsilylthio)aniline,N-methylidene-3-(trimethylsilylthio)aniline,N-methylidene-4-(trimethylsilylthio)aniline,N-methylidene-1-(trimethylsilylthio)naphthalen-8-amine,N-methylidene-2-(trimethylsilylthio)naphthalen-1-amine,N-eth-2-ylidene-2-(trimethylsilylthio)aniline,N-eth-2-ylidene-3-(trimethylsilylthio)aniline,N-eth-2-ylidene-4-(trimethylsilylthio)aniline,N-eth-2-ylidene-1-(trimethylsilylthio)naphthalen-8-amine,N-eth-2-ylidene-2-(trimethylsilylthio)naphthalen-1-amine,N-prop-3-ylidene-2-(trimethylsilylthio)aniline,N-prop-3-ylidene-3-(trimethylsilylthio)aniline,N-prop-3-ylidene-4-(trimethylsilylthio)aniline,N-prop-3-ylidene-1-(trimethylsilylthio)naphthalen-8-amine,N-prop-3-ylidene-2-(trimethylsilylthio)naphthalen-1-amine,N-but-4-ylidene-2-(trimethylsilylthio)aniline,N-but-4-ylidene-3-(trimethylsilylthio)aniline,N-but-4-ylidene-4-(trimethylsilylthio)aniline,N-but-4-ylidene-1-(trimethylsilylthio)naphthalen-8-amine,N-but-4-ylidene-2-(trimethylsilylthio)naphthalen-1-amine,N-pent-5-ylidene-2-(trimethylsilylthio)aniline,N-pent-5-ylidene-3-(trimethylsilylthio)aniline,N-pent-5-ylidene-4-(trimethylsilylthio)aniline,N-pent-5-ylidene-1-(trimethylsilylthio)naphthalen-8-amine, andN-pent-5-ylidene-2-(trimethylsilylthio)naphthalen-1-amine.

Representative examples of N-[silylthiocyclohydrocarbylidene)alkylaminesinclude the cis and trans isomers ofN-[2-(trimethylsilylthio)cyclohexylidene]methylamine,N-[3-(trimethylsilylthio)cyclohexylidene]methylamine,N-[4-(trimethylsilylthio)cyclohexylidene]methylamine,N-[2-(trimethylsilylthio)cyclopentylidene]methylamine,N-[3-(trimethylsilylthio)cyclohpentylidene]methylamine,N-[2-(trimethylsilylthio)cycloheptylidene]methylamine,N-[3-(trimethylsilylthio)cycloheptylidene]methylamine,N-[2-(trimethylsilylthio)cyclopropylidene]methylamine,N-[3-(trimethylsilylthio)cyclopropylidene]methylamine,N-[2-(trimethylsilylthio)cyclohexylidene]-n-butylamine,N-[3-(trimethylsilylthio)cyclohexylidene]-n-butylamine,N-[4-(trimethylsilylthio)cyclohexylidene]-n-butylamine,N-[2-(trimethylsilylthio)cyclopentylidene]-n-butylamine,N-[3-(trimethylsilylthio)cyclohpentylidene]-n-butylamine,N-[2-(trimethylsilylthio)cycloheptylidene]-n-butylamine,N-[3-(trimethylsilylthio)cycloheptylidene]-n-butylamine,N-[2-(trimethylsilylthio)cyclopropylidene]-n-butylamine,N-[3-(trimethylsilylthio)cyclopropylidene]-n-butylamine,N-[2-(trimethylsilylthio)cyclohexylidene]-n-pentylamine,N-[3-(trimethylsilylthio)cyclohexylidene]-n-pentylamine,N-[4-(trimethylsilylthio)cyclohexylidene]-n-pentylamine,N-[2-(trimethylsilylthio)cyclopentylidene]-n-pentylamine,N-[3-(trimethylsilylthio)cyclohpentylidene]-n-pentylamine,N-[2-(trimethylsilylthio)cycloheptylidene]-n-pentylamine,N-[3-(trimethylsilylthio)cycloheptylidene]-n-pentylamine,N-[2-(trimethylsilylthio)cyclopropylidene]-n-pentylamine,N-[3-(trimethylsilylthio)cyclopropylidene]-n-pentylamine,N-[2-(trimethylsilylthio)cyclohexylidene]-n-hexylamine,N-[3-(trimethylsilylthio)cyclohexylidene]-n-hexylamine,N-[4-(trimethylsilylthio)cyclohexylidene]-n-hexylamine,N-[2-(trimethylsilylthio)cyclopentylidene]-n-hexylamine,N-[3-(trimethylsilylthio)cyclohpentylidene]-n-hexylamine,N-[2-(trimethylsilylthio)cycloheptylidene]-n-hexylamine,N-[3-(trimethylsilylthio)cycloheptylidene]-n-hexylamine,N-[2-(trimethylsilylthio)cyclopropylidene]-n-hexylamine,N-[3-(trimethylsilylthio)cyclopropylidene]-n-hexylamine,N-[2-(trimethylsilylthio)cyclohexylidene]cyclopropylamine,N-[3-(trimethylsilylthio)cyclohexylidene]cyclopropylamine,N-[4-(trimethylsilylthio)cyclohexylidene]cyclopropylamine,N-[2-(trimethylsilylthio)cyclopentylidene]cyclopropylamine,N-[3-(trimethylsilylthio)cyclohpentylidene]cyclopropylamine,N-[2-(trimethylsilylthio)cycloheptylidene]cyclopropylamine,N-[3-(trimethylsilylthio)cycloheptylidene]cyclopropylamine,N-[2-(trimethylsilylthio)cyclopropylidene]cyclopropylamine,N-[3-(trimethylsilylthio)cyclopropylidene]cyclopropylamine,N-[2-(trimethylsilylthio)cyclohexylidene]cyclopentylamine,N-[3-(trimethylsilylthio)cyclohexylidene]cyclopentylamine,N-[4-(trimethylsilylthio)cyclohexylidene]cyclopentylamine,N-[2-(trimethylsilylthio)cyclopentylidene]cyclopentylamine,N-[3-(trimethylsilylthio)cyclohpentylidene]cyclopentylamine,N-[2-(trimethylsilylthio)cycloheptylidene]cyclopentylamine,N-[3-(trimethylsilylthio)cycloheptylidene]cyclopentylamine,N-[2-(trimethylsilylthio)cyclopropylidene]cyclopentylamine,N-[3-(trimethylsilylthio)cyclopropylidene]cyclopentylamine,N-[2-(trimethylsilylthio)cyclohexylidene]cyclohexylamine,N-[3-(trimethylsilylthio)cyclohexylidene]cyclohexylamine,N-[4-(trimethylsilylthio)cyclohexylidene]cyclohexylamine,N-[2-(trimethylsilylthio)cyclopentylidene]cyclohexylamine,N-[3-(trimethylsilylthio)cyclohpentylidene]cyclohexylamine,N-[2-(trimethylsilylthio)cycloheptylidene]cyclohexylamine,N-[3-(trimethylsilylthio)cycloheptylidene]cyclohexylamine,N-[2-(trimethylsilylthio)cyclopropylidene]cyclohexylamine,N-[3-(trimethylsilylthio)cyclopropylidene]cyclohexylamine,N-[2-(trimethylsilylthio)cyclohexylidene]cycloheptylamine,N-[3-(trimethylsilylthio)cyclohexylidene]cycloheptylamine,N-[4-(trimethylsilylthio)cyclohexylidene]cycloheptylamine,N-[2-(trimethylsilylthio)cyclopentylidene]cycloheptylamine,N-[3-(trimethylsilylthio)cyclohpentylidene]cycloheptylamine,N-[2-(trimethylsilylthio)cycloheptylidene]cycloheptylamine,N-[3-(trimethylsilylthio)cycloheptylidene]cycloheptylamine,N-[2-(trimethylsilylthio)cyclopropylidene]cycloheptylamine, andN-[3-(trimethylsilylthio)cyclopropylidene]cycloheptylamine.

Representative examples of N-(silylthiocyclohydrocarbylidene) arylaminesinclude the cis and trans isomers ofN-[2-(trimethylsilylthio)cyclohexylidene]aniline,N-[3-(trimethylsilylthio)cyclohexylidene]aniline,N-[4-(trimethylsilylthio)cyclohexylidene]aniline,N-[2-(trimethylsilylthio)cyclopentylidene]aniline,N-[3-(trimethylsilylthio)cyclohpentylidene]aniline,N-[2-(trimethylsilylthio)cycloheptylidene]aniline,N-[3-(trimethylsilylthio)cycloheptylidene]aniline,N-[2-(trimethylsilylthio)cyclopropylidene]aniline,N-[3-(trimethylsilylthio)cyclopropylidene]aniline,N-[2-(trimethylsilylthio)cyclohexylidene]-2-methylaniline,N-[3-(trimethylsilylthio)cyclohexylidene]-2-methylaniline,N-[4-(trimethylsilylthio)cyclohexylidene]-2-methylaniline,N-[2-(trimethylsilylthio)cyclopentylidene]-2-methylaniline,N-[3-(trimethylsilylthio)cyclohpentylidene]-2-methylaniline,N-[2-(trimethylsilylthio)cycloheptylidene]-2-methylaniline,N-[3-(trimethylsilylthio)cycloheptylidene]-2-methylaniline,N-[2-(trimethylsilylthio)cyclopropylidene]-2-methylaniline,N-[3-(trimethylsilylthio)cyclopropylidene]-2-methylaniline,N-[2-(trimethylsilylthio)cyclohexylidene]-3-methylaniline,N-[3-(trimethylsilylthio)cyclohexylidene]-3-methylaniline,N-[4-(trimethylsilylthio)cyclohexylidene]-3-methylaniline,N-[2-(trimethylsilylthio)cyclopentylidene]-3-methylaniline,N-[3-(trimethylsilylthio)cyclohpentylidene]-3-methylaniline,N-[2-(trimethylsilylthio)cycloheptylidene]-3-methylaniline,N-[3-(trimethylsilylthio)cycloheptylidene]-3-methylaniline,N-[2-(trimethylsilylthio)cyclopropylidene]-3-methylaniline,N-[3-(trimethylsilylthio)cyclopropylidene]-3-methylaniline,N-[2-(trimethylsilylthio)cyclohexylidene]-4-methylaniline,N-[3-(trimethylsilylthio)cyclohexylidene]-4-methylaniline,N-[4-(trimethylsilylthio)cyclohexylidene]-4-methylaniline,N-[2-(trimethylsilylthio)cyclopentylidene]-4-methylaniline,N-[3-(trimethylsilylthio)cyclohpentylidene]-4-methylaniline,N-[2-(trimethylsilylthio)cycloheptylidene]-4-methylaniline,N-[3-(trimethylsilylthio)cycloheptylidene]-4-methylaniline,N-[2-(trimethylsilylthio)cyclopropylidene]-4-methylaniline,N-[3-(trimethylsilylthio)cyclopropylidene]-4-methylaniline,N-[2-(trimethylsilylthio)cyclohexylidene]benzylamine,N-[3-(trimethylsilylthio)cyclohexylidene]benzylamine,N-[4-(trimethylsilylthio)cyclohexylidene]benzylamine,N-[2-(trimethylsilylthio)cyclopentylidene]benzylamine,N-[3-(trimethylsilylthio)cyclohpentylidene]benzylamine,N-[2-(trimethylsilylthio)cycloheptylidene]benzylamine,N-[3-(trimethylsilylthio)cycloheptylidene]benzylamine,N-[2-(trimethylsilylthio)cyclopropylidene]benzylamine, andN-[3-(trimethylsilylthio)cyclopropylidene]benzylamine.

Representative examples of N-cyclohydrocarbylidene(silylthioalkyl)amines include the cis and trans isomers ofN-cyclohexylidene[(trimethylsilylthio)methyl]amine,N-cyclohexylidene[2-(trimethylsilylthio)ethyl]amine,N-cyclohexylidene[2-(trimethylsilylthio)propyl]amine,N-cyclohexylidene[3-(trimethylsilylthio)propyl]amine,N-cyclohexylidene[2-(trimethylsilylthio)pentyl]amine,N-cyclohexylidene[3-(trimethylsilylthio)pentyl]amine,N-cyclohexylidene[4-(trimethylsilylthio)pentyl]amine,N-cyclohexylidene[5-(trimethylsilylthio)pentyl]amine,N-cyclohexylidene[4-(trimethylsilylthio)cyclohexyl]amine,N-cyclopentylidene[(trimethylsilylthio)methyl]amine,N-cyclopentylidene[2-(trimethylsilylthio)ethyl]amine,N-cyclopentylidene[2-(trimethylsilylthio)propyl]amine,N-cyclopentylidene[3-(trimethylsilylthio)propyl]amine,N-cyclopentylidene[2-(trimethylsilylthio)pentyl]amine,N-cyclopentylidene[3-(trimethylsilylthio)pentyl]amine,N-cyclopentylidene[4-(trimethylsilylthio)pentyl]amine,N-cyclopentylidene[5-(trimethylsilylthio)pentyl]amine,N-cyclopentylidene[4-(trimethylsilylthio)cyclohexyl]amine,

Representative examples of N-cyclohydrocarbylidene (silylthioaryl)amines include the cis and trans isomers ofN-cyclopropylidene-2-(trimethylsilylthio)aniline,N-cyclopropylidene-3-(trimethylsilylthio)aniline,N-cyclopropylidene-4-(trimethylsilylthio)aniline,N-cyclopropylidene-1-(trimethylsilylthio)naphthalen-8-amine,N-cyclopropylidene-2-(trimethylsilylthio)naphthalen-1-amine,N-cyclohexylidene-2-(trimethylsilylthio)aniline,N-cyclohexylidene-3-(trimethylsilylthio)aniline,N-cyclohexylidene-4-(trimethylsilylthio)aniline,N-cyclohexylidene-1-(trimethylsilylthio)naphthalen-8-amine,N-cyclohexylidene-2-(trimethylsilylthio)naphthalen-1-amine,N-cyclopentylidene-2-(trimethylsilylthio)aniline,N-cyclopentylidene-3-(trimethylsilylthio)aniline,N-cyclopentylidene-4-(trimethylsilylthio)aniline,N-cyclopentylidene-1-(trimethylsilylthio)naphthalen-8-amine, andN-cyclopentylidene-2-(trimethylsilylthio)naphthalen-1-amine.

In one or more embodiments, the imine compound containing a protectedthiol group may be prepared by first reacting, via a condensationreaction, (i) a compound containing a thiol group and an amine groupwith (ii) a compound containing an aldehyde group (i.e. —C(H)=0) or aketone group (i.e. —C(R)=0). Typically, one equivliennt of the aldehydeor ketone group can be reacted with one equivliennt of the amine groupto form a condensation product, which is an imine compound containing athiol group. The thiol group of the imine compound containing a thiolgroup may then be protected to form the imine compound containing aprotected thiol group. For example, the thiol group may be protectedthrough a silylating reaction to form an imine compound containing aprotected thiol group.

The amount of the imine compound containing a protected thiol group thatcan be added to the polymerization mixture to yield the functionalizedpolymer of this invention may depend on various factors including thetype and amount of catalyst or initiator used to synthesize the reactivepolymer and the desired degree of functionalization. In one or moreembodiments, where the reactive polymer is prepared by employing alanthanide-based catalyst, the amount of the imine compound containing aprotected thiol group employed can be described with reference to thelanthanide metal of the lanthanide-containing compound. For example, themolar ratio of the imine compound containing a protected thiol group tothe lanthanide metal may be from about 1:1 to about 200:1, in otherembodiments from about 5:1 to about 150:1, and in other embodiments fromabout 10:1 to about 100:1.

In other embodiments, such as where the reactive polymer is prepared byusing an anionic initiator, the amount of the imine compound containinga protected thiol group employed can be described with reference to theamount of metal cation associated with the initiator. For example, wherean organolithium initiator is employed, the molar ratio of the iminecompound containing a protected thiol group to the lithium cation may befrom about 0.3:1 to about 2:1, in other embodiments from about 0.6:1 toabout 1.5:1, and in other embodiments from 0.8:1 to about 1.2:1.

In one or more embodiments, in addition to the imine compound containinga protected thiol group, a co-functionalizing agent may also be added tothe polymerization mixture to yield a functionalized polymer withtailored properties. A mixture of two or more co-functionalizing agentsmay also be employed. The co-functionalizing agent may be added to thepolymerization mixture prior to, together with, or after theintroduction of the imine compound containing a protected thiol group.In one or more embodiments, the co-functionalizing agent is added to thepolymerization mixture at least 5 minutes after, in other embodiments atleast 10 minutes after, and in other embodiments at least 30 minutesafter the introduction of the imine compound containing a protectedthiol group.

In one or more embodiments, co-functionalizing agents include compoundsor reagents that can react with a reactive polymer produced by thisinvention and thereby provide the polymer with a functional group thatis distinct from a propagating chain that has not been reacted with theco-functionalizing agent. The functional group may be reactive orinteractive with other polymer chains (propagating and/ornon-propagating) or with other constituents such as reinforcing fillers(e.g. carbon black) that may be combined with the polymer. In one ormore embodiments, the reaction between the co-functionalizing agent andthe reactive polymer proceeds via an addition or substitution reaction.

Useful co-functionalizing agents may include compounds that simplyprovide a functional group at the end of a polymer chain without joiningtwo or more polymer chains together, as well as compounds that cancouple or join two or more polymer chains together via a functionallinkage to form a single macromolecule. The latter type ofco-functionalizing agents may also be referred to as coupling agents.

In one or more embodiments, co-functionalizing agents include compoundsthat will add or impart a heteroatom to the polymer chain. In particularembodiments, co-functionalizing agents include those compounds that willimpart a functional group to the polymer chain to form a functionalizedpolymer that reduces the 50° C. hysteresis loss of a carbon-black filledvulcanizates prepared from the functionalized polymer as compared tosimilar carbon-black filled vulcanizates prepared fromnon-functionalized polymer. In one or more embodiments, this reductionin hysteresis loss is at least 5%, in other embodiments at least 10%,and in other embodiments at least 15%.

In one or more embodiments, suitable co-functionalizing agents includethose compounds that contain groups that may react with the reactivepolymers produced in accordance with this invention. Exemplaryco-functionalizing agents include ketones, quinones, aldehydes, amides,esters, isocyanates, isothiocyanates, epoxides, imines, aminoketones,aminothioketones, and acid anhydrides. Examples of these compounds aredisclosed in U.S. Pat. Nos. 4,906,706, 4,990,573, 5,064,910, 5,567,784,5,844,050, 6,838,526, 6,977,281, and 6,992,147; U.S. Pat. PublicationNos. 2006/0004131 A1, 2006/0025539 A1, 2006/0030677 A1, and 2004/0147694A1; Japanese Patent Application Nos. 05-051406A, 05-059103A, 10-306113A,and 11-035633A; which are incorporated herein by reference. Otherexamples of co-functionalizing agents include azine compounds asdescribed in U.S. Pat. No. 7,879,952, hydrobenzamide compounds asdisclosed in U.S. Pat. No. 7,671,138, nitro compounds as disclosed inU.S. Pat. No. 7,732,534, and protected oxime compounds as disclosed inU.S. Pat. No. 8,088,868, all of which are incorporated herein byreference.

In particular embodiments, the co-functionalizing agents employed may bemetal halides, metalloid halides, alkoxysilanes, metal carboxylates,hydrocarbylmetal carboxylates, hydrocarbylmetal ester-carboxylates, andmetal alkoxides.

Exemplary metal halide compounds include tin tetrachloride, tintetrabromide, tin tetraiodide, n-butyltin trichloride, phenyltintrichloride, di-n-butyltin dichloride, diphenyltin dichloride,tri-n-butyltin chloride, triphenyltin chloride, germanium tetrachloride,germanium tetrabromide, germanium tetraiodide, n-butylgermaniumtrichloride, di-n-butylgermanium dichloride, and tri-n-butylgermaniumchloride.

Exemplary metalloid halide compounds include silicon tetrachloride,silicon tetrabromide, silicon tetraiodide, methyltrichlorosilane,phenyltrichlorosilane, dimethyldichlorosilane, diphenyldichlorosilane,boron trichloride, boron tribromide, boron triiodide, phosphoroustrichloride, phosphorous tribromide, and phosphorus triiodide.

In one or more embodiments, the alkoxysilanes may include at least onegroup selected from the group consisting of an epoxy group and anisocyanate group.

Exemplary alkoxysilane compounds including an epoxy group include(3-glycidyloxypropyl)trimethoxysilane,(3-glycidyloxypropyl)triethoxysilane,(3-glycidyloxypropyl)triphenoxysilane,(3-glycidyloxypropyl)methyldimethoxysilane,(3-glycidyloxypropyl)methyldiethoxysilane,(3-glycidyloxypropyl)methyldiphenoxysilane,[2-(3,4-epoxycyclohexyl)ethyl]trimethoxysilane, and[2-ethyl]triethoxysilane.

Exemplary alkoxysilane compounds including an isocyanate group include(3-isocyanatopropyl)trimethoxysilane,(3-isocyanatopropyl)triethoxysilane,(3-isocyanatopropyl)triphenoxysilane,(3-isocyanatopropyl)methyldimethoxysilane,(3-isocyanatopropyl)methyldiethoxysilane(3-isocyanatopropyl)methyldiphenoxysilane, and(isocyanatomethyl)methyldimethoxysilane.

Exemplary metal carboxylate compounds include tin tetraacetate, tinbis(2-ethylhexanaote), and tin bis(neodecanoate).

Exemplary hydrocarbylmetal carboxylate compounds include triphenyltin2-ethylhexanoate, tri-n-butyltin 2-ethylhexanoate, tri-n-butyltinneodecanoate, triisobutyltin 2-ethylhexanoate, diphenyltinbis(2-ethylhexanoate), di-n-butyltin bis(2-ethylhexanoate),di-n-butyltin bis(neodecanoate), phenyltin tris(2-ethylhexanoate), andn-butyltin tris(2-ethylhexanoate).

Exemplary hydrocarbylmetal ester-carboxylate compounds includedi-n-butyltin bis(n-octylmaleate), di-n-octyltin bis(n-octylmaleate),diphenyltin bis(n-octylmaleate), di-n-butyltin bis(2-ethylhexylmaleate),di-n-octyltin bis(2-ethylhexylmaleate), and diphenyltinbis(2-ethylhexylmaleate).

Exemplary metal alkoxide compounds include dimethoxytin, diethoxytin,tetraethoxytin, tetra-n-propoxytin, tetraisopropoxytin,tetra-n-butoxytin, tetraisobutoxytin, tetra-t-butoxytin, andtetraphenoxytin.

The amount of the co-functionalizing agent that can be added to thepolymerization mixture may depend on various factors including the typeand amount of catalyst or initiator used to synthesize the reactivepolymer and the desired degree of functionalization. In one or moreembodiments, where the reactive polymer is prepared by employing alanthanide-based catalyst, the amount of the co-functionalizing agentemployed can be described with reference to the lanthanide metal of thelanthanide-containing compound. For example, the molar ratio of theco-functionalizing agent to the lanthanide metal may be from about 1:1to about 200:1, in other embodiments from about 5:1 to about 150:1, andin other embodiments from about 10:1 to about 100:1.

In other embodiments, such as where the reactive polymer is prepared byusing an anionic initiator, the amount of the co-functionalizing agentemployed can be described with reference to the amount of metal cationassociated with the initiator. For example, where an organolithiuminitiator is employed, the molar ratio of the co-functionalizing agentto the lithium cation may be from about 0.3:1 to about 2:1, in otherembodiments from about 0.6:1 to about 1.5:1, and in other embodimentsfrom 0.8:1 to about 1.2:1.

The amount of the co-functionalizing agent employed can also bedescribed with reference to the imine compound containing a protectedthiol group. In one or more embodiments, the molar ratio of theco-functionalizing agent to the imine compound containing a protectedthiol group may be from about 0.05:1 to about 1:1, in other embodimentsfrom about 0.1:1 to about 0.8:1, and in other embodiments from about0.2:1 to about 0.6:1.

In one or more embodiments, the imine compound containing a protectedthiol group (and optionally the co-functionalizing agent) may beintroduced to the polymerization mixture at a location (e.g., within avessel) where the polymerization has been conducted. In otherembodiments, the imine compound containing a protected thiol group maybe introduced to the polymerization mixture at a location that isdistinct from where the polymerization has taken place. For example,imine compound containing a protected thiol group may be introduced tothe polymerization mixture in downstream vessels including downstreamreactors or tanks, in-line reactors or mixers, extruders, ordevolatilizers.

In one or more embodiments, the imine compound containing a protectedthiol group (and optionally the co-functionalizing agent) can be reactedwith the reactive polymer after a desired monomer conversion is achievedbut before the polymerization mixture is quenched by a quenching agent.In one or more embodiments, the reaction between the imine compoundcontaining a protected thiol group and the reactive polymer may takeplace within 30 minutes, in other embodiments within 5 minutes, and inother embodiments within one minute after the peak polymerizationtemperature is reached. In one or more embodiments, the reaction betweenimine compound containing a protected thiol group and the reactivepolymer can occur once the peak polymerization temperature is reached.In other embodiments, the reaction between the imine compound containinga protected thiol group and the reactive polymer can occur after thereactive polymer has been stored. In one or more embodiments, thestorage of the reactive polymer occurs at room temperature or below roomtemperature under an inert atmosphere. In one or more embodiments, thereaction between the imine compound containing a protected thiol groupand the reactive polymer may take place at a temperature from about 10°C. to about 150° C., and in other embodiments from about 20° C. to about100° C. The time required for completing the reaction between the iminecompound containing a protected thiol group and the reactive polymerdepends on various factors such as the type and amount of the catalystor initiator used to prepare the reactive polymer, the type and amountof the imine compound containing a protected thiol group, as well as thetemperature at which the functionalization reaction is conducted. In oneor more embodiments, the reaction between the imine compound containinga protected thiol group and the reactive polymer can be conducted forabout 10 to 60 minutes.

In one or more embodiments, after the reaction between the reactivepolymer and the imine compound containing a protected thiol group (andoptionally the co-functionalizing agent) has been accomplished orcompleted, a quenching agent can be added to the polymerization mixturein order to protonate the reaction product between the reactive polymerand the imine compound containing a protected thiol group, inactivateany residual reactive polymer chains, and/or inactivate the catalyst orcatalyst components. The quenching agent may include a protic compound,which includes, but is not limited to, an alcohol, a carboxylic acid, aninorganic acid, water, or a mixture thereof. An antioxidant such as2,6-di-tert-butyl-4-methylphenol may be added along with, before, orafter the addition of the quenching agent. The amount of the antioxidantemployed may be in the range of 0.2% to 1% by weight of the polymerproduct. Additionally, the polymer product can be oil extended by addingan oil to the polymer, which may be in the form of a polymer cement orpolymer dissolved or suspended in monomer. Practice of the presentinvention does not limit the amount of oil that may be added, andtherefore conventional amounts may be added (e.g., 5-50 phr). Usefuloils or extenders that may be employed include, but are not limited to,aromatic oils, paraffinic oils, naphthenic oils, vegetable oils otherthan castor oils, low PCA oils including MES, TDAE, and SRAE, and heavynaphthenic oils.

Once the polymerization mixture has been quenched, the variousconstituents of the polymerization mixture may be recovered. In one ormore embodiments, the unreacted monomer can be recovered from thepolymerization mixture. For example, the monomer can be distilled fromthe polymerization mixture by using techniques known in the art. In oneor more embodiments, a devolatilizer may be employed to remove themonomer from the polymerization mixture. Once the monomer has beenremoved from the polymerization mixture, the monomer may be purified,stored, and/or recycled back to the polymerization process.

The polymer product may be recovered from the polymerization mixture byusing techniques known in the art. In one or more embodiments,desolventization and drying techniques may be used. For instance, thepolymer can be recovered by passing the polymerization mixture through aheated screw apparatus, such as a desolventizing extruder, in which thevolatile substances are removed by evaporation at appropriatetemperatures (e.g., about 100° C. to about 170° C.) and underatmospheric or sub-atmospheric pressure. This treatment serves to removeunreacted monomer as well as any low-boiling solvent. Alternatively, thepolymer can also be recovered by subjecting the polymerization mixtureto steam desolventization, followed by drying the resulting polymercrumbs in a hot air tunnel. The polymer can also be recovered bydirectly drying the polymerization mixture on a drum dryer.

The reactive polymer and the imine compound containing a protected thiolgroup (and optionally the co-functionalizing agent) are believed toreact to produce a novel functionalized polymer, wherein the residue ofthe imine compound containing a protected thiol group is imparted to theend of the polymer chain. It is believed that the reactive end of thepolymer chain reacts with the imine compound containing a protectedthiol group. Nonetheless, the exact chemical structure of thefunctionalized polymer produced in every embodiment is not known withany great degree of certainty, particularly as the structure relates tothe residue imparted to the polymer chain end by the imine compoundcontaining a protected thiol group and optionally the co-functionalizingagent. Indeed, it is speculated that the structure of the functionalizedpolymer may depend upon various factors such as the conditions employedto prepare the reactive polymer (e.g., the type and amount of thecatalyst or initiator) and the conditions employed to react the iminecompound containing a protected thiol group (and optionally theco-functionalizing agent) with the reactive polymer (e.g., the types andamounts of the imine compound containing a protected thiol group and theco-functionalizing agent). The functionalized polymer resulting from thereaction between the reactive polymer and imine compound containing aprotected thiol group can be protonated or further modified.

In one or more embodiments, the functionalized polymers preparedaccording to this invention may contain unsaturation. In these or otherembodiments, the functionalized polymers are vulcanizable. In one ormore embodiments, the functionalized polymers can have a glasstransition temperature (T_(g)) that is less than 0° C., in otherembodiments less than −20° C., and in other embodiments less than −30°C. In one embodiment, these polymers may exhibit a single glasstransition temperature. In particular embodiments, the polymers may behydrogenated or partially hydrogenated.

In one or more embodiments, the functionalized polymers of thisinvention may be cis-1,4-polydienes having a cis-1,4-linkage contentthat is greater than 60%, in other embodiments greater than about 75%,in other embodiments greater than about 90%, and in other embodimentsgreater than about 95%, where the percentages are based upon the numberof diene mer units adopting the cis-1,4 linkage versus the total numberof diene mer units. Also, these polymers may have a 1,2-linkage contentthat is less than about 7%, in other embodiments less than 5%, in otherembodiments less than 2%, and in other embodiments less than 1%, wherethe percentages are based upon the number of diene mer units adoptingthe 1,2-linkage versus the total number of diene mer units. The balanceof the diene mer units may adopt the trans-1,4-linkage. The cis-1,4-,1,2-, and trans-1,4-linkage contents can be determined by infraredspectroscopy. The number average molecular weight (M_(n)) of thesepolymers may be from about 1,000 to about 1,000,000, in otherembodiments from about 5,000 to about 200,000, in other embodiments fromabout 25,000 to about 150,000, and in other embodiments from about50,000 to about 120,000, as determined by using gel permeationchromatography (GPC) calibrated with polystyrene standards andMark-Houwink constants for the polymer in question. The molecular weightdistribution or polydispersity (M_(w)/M_(n)) of these polymers may befrom about 1.5 to about 5.0, and in other embodiments from about 2.0 toabout 4.0.

In one or more embodiments, the functionalized polymers of thisinvention may be polydienes having medium or low cis-1,4-linkagecontents. These polymers, which can be prepared by anionicpolymerization techniques, can have a cis-1,4-linkage content of fromabout 10% to 60%, in other embodiments from about 15% to 55%, and inother embodiments from about 20% to about 50%. These polydienes may alsohave a 1,2-linkage content from about 10% to about 90%, in otherembodiments from about 10% to about 60%, in other embodiments from about15% to about 50%, and in other embodiments from about 20% to about 45%.In particular embodiments, where the polydienes are prepared byemploying a functional anionic initiator, the head of the polymer chainincludes a functional group that is the residue of the functionalinitiator.

In particular embodiments, the functionalized polymers of this inventionare copolymers of 1,3-butadiene, styrene, and optionally isoprene. Thesemay include random copolymers and block copolymers.

Advantageously, the functionalized polymers of this invention mayprovide rubber compositions that demonstrate reduced hysteresis. Thefunctionalized polymers are particularly useful in preparing rubbercompositions that can be used to manufacture tire components. Rubbercompounding techniques and the additives employed therein are generallydisclosed in The Compounding and Vulcanization of Rubber, in RubberTechnology (2^(nd) Ed. 1973).

The rubber compositions can be prepared by using the functionalizedpolymers alone or together with other elastomers (i.e., polymers thatcan be vulcanized to form compositions possessing rubbery or elastomericproperties). Other elastomers that may be used include natural andsynthetic rubbers. The synthetic rubbers typically derive from thepolymerization of conjugated diene monomer, the copolymerization ofconjugated diene monomer with other monomer such as vinyl-substitutedaromatic monomer, or the copolymerization of ethylene with one or moreα-olefins and optionally one or more diene monomers.

Exemplary elastomers include natural rubber, synthetic polyisoprene,polybutadiene, polyisobutylene-co-isoprene, neoprene,poly(ethylene-co-propylene), poly(styrene-co-butadiene),poly(styrene-co-isoprene), poly(styrene-co-isoprene-co-butadiene),poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene),polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber,epichlorohydrin rubber, and mixtures thereof. These elastomers can havea myriad of macromolecular structures including linear, branched, andstar-shaped structures.

The rubber compositions may include fillers such as inorganic andorganic fillers. Examples of organic fillers include carbon black andstarch. Examples of inorganic fillers include silica, aluminumhydroxide, magnesium hydroxide, mica, talc (hydrated magnesiumsilicate), and clays (hydrated aluminum silicates). Carbon blacks andsilicas are the most common fillers used in manufacturing tires. Incertain embodiments, a mixture of different fillers may beadvantageously employed.

In one or more embodiments, carbon blacks include furnace blacks,channel blacks, and lamp blacks. More specific examples of carbon blacksinclude super abrasion furnace blacks, intermediate super abrasionfurnace blacks, high abrasion furnace blacks, fast extrusion furnaceblacks, fine furnace blacks, semi-reinforcing furnace blacks, mediumprocessing channel blacks, hard processing channel blacks, conductingchannel blacks, and acetylene blacks.

In particular embodiments, the carbon blacks may have a surface area(EMSA) of at least 20 m²/g and in other embodiments at least 35 m²/g;surface area values can be determined by ASTM D-1765 using thecetyltrimethylammonium bromide (CTAB) technique. The carbon blacks maybe in a pelletized form or an unpelletized flocculent form. Thepreferred form of carbon black may depend upon the type of mixingequipment used to mix the rubber compound.

The amount of carbon black employed in the rubber compositions can be upto about 50 parts by weight per 100 parts by weight of rubber (phr),with about 5 to about 40 phr being typical.

Some commercially available silicas which may be used include Hi-Sil™215, Hi-Sil™ 233, and Hi-Sil™ 190 (PPG Industries, Inc.; Pittsburgh,Pa.). Other suppliers of commercially available silica include GraceDavison (Baltimore, Md.), Degussa Corp. (Parsippany, N.J.), RhodiaSilica Systems (Cranbury, N.J.), and J. M. Huber Corp. (Edison, N.J.).

In one or more embodiments, silicas may be characterized by theirsurface areas, which give a measure of their reinforcing character. TheBrunauer, Emmet and Teller (“BET”) method (described in J. Am. Chem.Soc., vol. 60, p. 309 et seq.) is a recognized method for determiningthe surface area. The BET surface area of silica is generally less than450 m²/g. Useful ranges of surface area include from about 32 to about400 m²/g, about 100 to about 250 m²/g, and about 150 to about 220 m²/g.

The pH's of the silicas are generally from about 5 to about 7 orslightly over 7, or in other embodiments from about 5.5 to about 6.8.

In one or more embodiments, where silica is employed as a filler (aloneor in combination with other fillers), a coupling agent and/or ashielding agent may be added to the rubber compositions during mixing inorder to enhance the interaction of silica with the elastomers. Usefulcoupling agents and shielding agents are disclosed in U.S. Pat. Nos.3,842,111, 3,873,489, 3,978,103, 3,997,581, 4,002,594, 5,580,919,5,583,245, 5,663,396, 5,674,932, 5,684,171, 5,684,172 5,696,197,6,608,145, 6,667,362, 6,579,949, 6,590,017, 6,525,118, 6,342,552, and6,683,135, which are incorporated herein by reference.

The amount of silica employed in the rubber compositions can be fromabout 1 to about 100 phr or in other embodiments from about 5 to about80 phr. The useful upper range is limited by the high viscosity impartedby silicas. When silica is used together with carbon black, the amountof silica can be decreased to as low as about 1 phr; as the amount ofsilica is decreased, lesser amounts of coupling agents and shieldingagents can be employed. Generally, the amounts of coupling agents andshielding agents range from about 4% to about 20% based on the weight ofsilica used.

A multitude of rubber curing agents (also called vulcanizing agents) maybe employed, including sulfur or peroxide-based curing systems. Curingagents are described in Kirk-Othmer, ENCYCLOPEDIA OF CHEMICALTECHNOLOGY, Vol. 20, pgs. 365-468, (3^(rd) Ed. 1982), particularlyVulcanization Agents and Auxiliary Materials, pgs. 390-402, and A. Y.Coran, Vulcanization, ENCYCLOPEDIA OF POLYMER SCIENCE AND ENGINEERING,(2^(nd) Ed. 1989), which are incorporated herein by reference.Vulcanizing agents may be used alone or in combination.

Other ingredients that are typically employed in rubber compounding mayalso be added to the rubber compositions. These include accelerators,accelerator activators, oils, plasticizer, waxes, scorch inhibitingagents, processing aids, zinc oxide, tackifying resins, reinforcingresins, fatty acids such as stearic acid, peptizers, and antidegradantssuch as antioxidants and antiozonants. In particular embodiments, theoils that are employed include those conventionally used as extenderoils, which are described above.

All ingredients of the rubber compositions can be mixed with standardmixing equipment such as Banbury or Brabender mixers, extruders,kneaders, and two-rolled mills. In one or more embodiments, theingredients are mixed in two or more stages. In the first stage (oftenreferred to as the masterbatch mixing stage), a so-called masterbatch,which typically includes the rubber component and filler, is prepared.To prevent premature vulcanization (also known as scorch), themasterbatch may exclude vulcanizing agents. The masterbatch may be mixedat a starting temperature of from about 25° C. to about 125° C. with adischarge temperature of about 135° C. to about 180° C. Once themasterbatch is prepared, the vulcanizing agents may be introduced andmixed into the masterbatch in a final mixing stage, which is typicallyconducted at relatively low temperatures so as to reduce the chances ofpremature vulcanization. Optionally, additional mixing stages, sometimescalled remills, can be employed between the masterbatch mixing stage andthe final mixing stage. One or more remill stages are often employedwhere the rubber composition includes silica as the filler. Variousingredients including the functionalized polymers of this invention canbe added during these remills.

The mixing procedures and conditions particularly applicable tosilica-filled tire formulations are described in U.S. Pat. Nos.5,227,425, 5,719,207, and 5,717,022, as well as European Patent No.890,606, all of which are incorporated herein by reference. In oneembodiment, the initial masterbatch is prepared by including thefunctionalized polymer of this invention and silica in the substantialabsence of coupling agents and shielding agents.

The rubber compositions prepared from the functionalized polymers ofthis invention are particularly useful for forming tire components suchas treads, subtreads, sidewalls, body ply skims, bead filler, and thelike. Preferably, the functional polymers of this invention are employedin tread and sidewall formulations. In one or more embodiments, thesetread or sidewall formulations may include from about 10% to about 100%by weight, in other embodiments from about 35% to about 90% by weight,and in other embodiments from about 50% to about 80% by weight of thefunctionalized polymer based on the total weight of the rubber withinthe formulation.

Where the rubber compositions are employed in the manufacture of tires,these compositions can be processed into tire components according toordinary tire manufacturing techniques including standard rubbershaping, molding and curing techniques. Typically, vulcanization iseffected by heating the vulcanizable composition in a mold; e.g., it maybe heated to about 140° C. to about 180° C. Cured or crosslinked rubbercompositions may be referred to as vulcanizates, which generally containthree-dimensional polymeric networks that are thermoset. The otheringredients, such as fillers and processing aids, may be evenlydispersed throughout the crosslinked network. Pneumatic tires can bemade as discussed in U.S. Pat. Nos. 5,866,171, 5,876,527, 5,931,211, and5,971,046, which are incorporated herein by reference.

In order to demonstrate the practice of the present invention, thefollowing examples have been prepared and tested. The examples shouldnot, however, be viewed as limiting the scope of the invention. Theclaims will serve to define the invention.

EXAMPLES Example 1 Synthesis oftrans-N-Benzylidene-2-(trimethylsilylthio)aniline (TMSSPhImine)

A mixture of 2-phenylthiazoline (4.35 g, 20.40 mmol) and triethylamine(4.13 g, 40.80 mmol) in dichloromethane (55 ml) was cooled with an icebath. To this mixture was added iodotrimethylsilane (8.17 g, 40.80mmol). The resulting mixture was stirred for 21 hours at roomtemperature and then evaporated under vacuum to dryness. The residue wasextracted with toluene, filtered, and evaporated under vacuum, yieldingtrans-N-benzylidene-2-(trimethylsilylthio)aniline (abbreviated asTMSSPhImine) as a pale-yellow solid (5.82 g, 100% yield). The ¹H NMRdata (C₆D₆, 25° C., referenced to tetramethylsilane) of the product arelisted as follows: δ 6.63-7.18 (multiplet, 9H, aromatic protons), 6.06(singlet, 1H, CH═N proton), 0.07 (singlet, 9H, Si—CH₃ protons). From the¹H NMR data, the structure of the product was determined to be asfollows:

Example 2 Synthesis oftrans-N-(2-Pyridylmethylidene)-2-(trimethylsilylthio)aniline(TMSSPyImine)

A mixture of 2-pyridylthiazoline (5.73 g, 26.75 mmol) and triethylamine(5.41 g, 53.50 mmol) in dichloromethane (60 ml) was cooled with an icebath. To this mixture was added iodotrimethylsilane (10.70 g, 53.50mmol). The resulting mixture was stirred for 21 hours at roomtemperature and then evaporated under vacuum to dryness. The residue wasextracted with toluene, filtered, and evaporated under vacuum, yieldingtrans-N-(2-pyridylmethylidene)-2-(trimethylsilylthio)aniline(abbreviated as TMSSPhImine) as highly viscous oil (7.7 g, 100% yield).The ¹H NMR data (C₆D₆, 25° C., referenced to tetramethylsilane) of theproduct are listed as follows: δ 8.35 (multiplet, 1H, CH═N proton), 7.32(multiplet, 1H, aromatic proton), 6.86-6.97 (multiplet, 3H, aromaticprotons), 6.74 (multiplet, 1H, aromatic proton), 6.64 (multiplet, 1H,aromatic proton), 6.45-6.50 (multiplet, 2H, aromatic protons), 0.06(singlet, 9H, Si—CH₃ protons). From the ¹H NMR data, the structure ofthe product was determined to be as follows:

Example 3 Synthesis of Unmodified cis-1,4-Polybutadiene

To a 2-gallon nitrogen-purged reactor equipped with turbine agitatorblades were added 1646 g of hexane and 2822 g of 22.5 wt % 1,3-butadienein hexane. A preformed catalyst was prepared by mixing 7.35 ml of 4.32 Mmethylaluminoxane in toluene, 1.52 g of 22.5 wt % 1,3-butadiene inhexane, 0.59 ml of 0.537 M neodymium versatate in cyclohexane, 6.67 mlof 1.0 M diisobutylaluminum hydride in hexane, and 1.27 ml of 1.0 Mdiethylaluminum chloride in hexane. The catalyst was aged for 15 minutesand charged into the reactor. The reactor jacket temperature was thenset to 65° C. About 60 minutes after addition of the catalyst, thepolymerization mixture was cooled to room temperature and quenched with30 ml of 12 wt % 2,6-di-tert-butyl-4-methylphenol solution inisopropanol. The resulting polymer cement was coagulated with 12 litersof isopropanol containing 5 g of 2,6-di-tert-butyl-4-methylphenol andthen drum-dried. The Mooney viscosity (ML₁₊₄) of the resulting polymerwas determined to be 28.7 at 100° C. by using a Alpha TechnologiesMooney viscometer with a large rotor, a one-minute warm-up time, and afour-minute running time. As determined by gel permeation chromatography(GPC), the polymer had a number average molecular weight (M_(n)) of108,400, a weight average molecular weight (M_(w)) of 220,100, and amolecular weight distribution (M_(w)/M_(n)) of 2.03. The infraredspectroscopic analysis of the polymer indicated a cis-1,4-linkagecontent of 94.6%, a trans-1,4-linkage content of 4.9%, and a 1,2-linkagecontent of 0.5%.

The cold-flow resistance of the polymer was measured by using a Scottplasticity tester. Approximately 2.5 g of the polymer was molded, at100° C. for 20 minutes, into a cylindrical button with a diameter of 15mm and a height of 12 mm. After cooling down to room temperature, thebutton was removed from the mold and placed in a Scott plasticity testerat room temperature. A 5-kg load was applied to the specimen. After 8minutes, the residual sample gauge (i.e., sample thickness) was measuredto be 1.60 mm. Generally, the residual sample gauge can be taken as anindication of the cold-flow resistance of the polymer, with a higherresidual sample gauge indicating better cold-flow resistance.

The properties of the resulting polymer are summarized in Table 1.

TABLE 1 Physical Properties of Unmodified cis-1,4-Polybutadiene ExampleNo. Example 3 Example 4 Example 5 Example 6 Polymer type unmodifiedunmodified unmodified unmodified ML₁₊₄ at 28.7 47.5 24.7 46.3 100° C.M_(n) 108,400 133,500 104,100 134,000 M_(w) 220,100 281,000 208,600257,600 M_(w)/M_(n) 2.03 2.10 2.01 1.92 % cis-1,4- 94.6 95.4 95.0 95.8linkage % trans-1,4- 4.9 4.2 4.5 3.7 linkage % 1,2-linkage 0.5 0.5 0.50.5 Cold-flow 1.70 2.16 1.60 2.14 gauge (mm at 8 min.)

Example 4 Synthesis of Unmodified cis-1,4-Polybutadiene

To a 2-gallon nitrogen-purged reactor equipped with turbine agitatorblades were added 1633 g of hexane and 2835 g of 22.4 wt % 1,3-butadienein hexane. A preformed catalyst was prepared by mixing 5.29 ml of 4.32 Mmethylaluminoxane in toluene, 1.10 g of 22.4 wt % 1,3-butadiene inhexane, 0.43 ml of 0.537 M neodymium versatate in cyclohexane, 4.80 mlof 1.0 M diisobutylaluminum hydride in hexane, and 0.91 ml of 1.0 Mdiethylaluminum chloride in hexane. The catalyst was aged for 15 minutesand charged into the reactor. The reactor jacket temperature was thenset to 65° C. About 80 minutes after addition of the catalyst, thepolymerization mixture was cooled to room temperature and quenched with30 ml of 12 wt % 2,6-di-tert-butyl-4-methylphenol solution inisopropanol. The resulting polymer cement was coagulated with 12 litersof isopropanol containing 5 g of 2,6-di-tert-butyl-4-methylphenol andthen drum-dried. The properties of the resulting polymer are summarizedin Table 1.

Example 5 Synthesis of Unmodified cis-1,4-Polybutadiene

Another unmodified cis-1,4-polybutadiene sample was prepared by using aprocedure similar to that of Example 3. The properties of the resultingpolymer are summarized in Table 1.

Example 6 Synthesis of Unmodified cis-1,4-Polybutadiene

Another unmodified cis-1,4-polybutadiene sample was prepared by using aprocedure similar to that of Example 4. The properties of the resultingpolymer are summarized in Table 1.

Example 7 Synthesis of cis-1,4-Polybutadiene Modified withtrans-N-Benzylidene-2-(trimethylsilylthio)aniline (TMSSPhImine)

To a 2-gallon nitrogen-purged reactor equipped with turbine agitatorblades were added 1143 g of hexane and 3325 g of 19.1 wt % 1,3-butadienein hexane. A preformed catalyst was prepared by mixing 7.35 ml of 4.32 Mmethylaluminoxane in toluene, 1.80 g of 19.1 wt % 1,3-butadiene inhexane, 0.59 ml of 0.537 M neodymium versatate in cyclohexane, 6.67 mlof 1.0 M diisobutylaluminum hydride in hexane, and 1.27 ml of 1.0 Mdiethylaluminum chloride in hexane. The catalyst was aged for 15 minutesand charged into the reactor. The reactor jacket temperature was thenset to 65° C. About 60 minutes after addition of the catalyst, thepolymerization mixture was cooled to room temperature.

About 353 g of the resulting unmodified polymer cement (i.e.,pseudo-living polymer cement) was transferred from the reactor to anitrogen-purged bottle, followed by addition of 4.94 ml of 0.40 Mtrans-N-benzylidene-2-(trimethylsilylthio)aniline (TMSSPhImine) intoluene. The bottle was tumbled for 30 minutes in a water bathmaintained at 65° C. The resulting polymer cement was quenched with 3 mlof 12 wt % 2,6-di-tert-butyl-4-methylphenol solution in isopropanol,coagulated with 2 liters of isopropanol containing 0.5 g of2,6-di-tert-butyl-4-methylphenol, and then drum-dried. The properties ofthe resulting polymer are summarized in Table 2.

TABLE 2 Physical Properties of Modified cis-1,4-Polybutadiene ExampleNo. Example 9 Example 10 Example 7 Example 8 (comparative) (comparative)Polymer type TMMSPhImine TMMSPyImine PhImine PyImine modified modifiedmodified modified ML₁₊₄ at 100° C. 35.5 39.5 26.6 21.9 M_(n) 105,200112,600 105,500 98,600 M_(w) 223,900 235,900 213,100 196,800 M_(w)/M_(n)2.13 2.10 2.02 2.00 % cis-1,4-linkage 95.2 95.2 94.5 94.4 % trans-1,4-4.3 4.3 5.0 5.1 linkage % 1,2-linkage 0.5 0.5 0.5 0.5 Cold-flow gauge2.46 2.42 1.67 1.56 (mm at 8 min.)

Example 8 Synthesis of cis-1,4-Polybutadiene Modified withtrans-N-(2-Pyridylmethylidene)-2-(trimethylsilylthio)aniline(TMSSPyImine)

A cis-1,4-polybutadiene sample modified withtrans-N-(2-pyridylmethylidene)-2-(trimethylsilylthio)aniline(TMSSPyImine) was prepared by using a procedure similar to that ofExample 7. The properties of the resulting polymer are summarized inTable 2.

Example 9 Comparative Example Synthesis of Cis-1,4-PolybutadieneModified with Trans-N-Benzylideneaniline (PhImine)

A cis-1,4-polybutadiene sample modified with trans-N-benzylideneaniline(abbreviated as PhImine) was prepared by using a procedure similar tothat of Example 4. The properties of the resulting polymer aresummarized in Table 2. The structure of PhImine is shown below.

Example 10 Comparative Example Synthesis of cis-1,4-PolybutadieneModified with trans-N-(2-Pyridylmethylidene)aniline (PyImine)

A cis-1,4-polybutadiene sample modified withtrans-N-(2-pyridylmethylidene)aniline (abbreviated as imine C) wasprepared by using a procedure similar to that of Example 4. Theproperties of the resulting polymer are summarized in Table 2. Thestructure of PyImine is shown below.

In FIG. 1, the cold-flow resistance of the cis-1,4-polybutadiene samplessynthesized in Examples 3-10 is plotted against the polymer Mooneyviscosity. The data indicate that, at the same polymer Mooney viscosity,the cis-1,4-polybutadiene samples modified with TMSSPhImine orTMMSPyImine show a significantly higher residual sample gauge value andaccordingly significantly better cold-flow resistance than theunmodified polymer. In contrast, the cis-1,4-polybutadiene samplesmodified with PhImine or PyImine provide essentially no improvement oronly small improvement in cold-flow resistance as compared to theunmodified polymer.

Examples 11-14 Compounding Evaluation of Cis-1,4-Polybutadiene Modifiedwith Trans-N-Benzylidene-2-(trimethylsilylthio)aniline (TMSSPhImine) andtrans-N-(2-Pyridylmethylidene)-2-(trimethylsilylthio)aniline(TMSSPyImine) vs Unmodified cis-1,4-Polybutadiene

The cis-1,4-polybutadiene samples produced in Examples 3, 4, 7, and 8were evaluated in a rubber compound filled with carbon black. Thecompositions of the vulcanizates are presented in Table 3, wherein thenumbers are expressed as parts by weight per hundred parts by weight oftotal rubber (phr).

TABLE 3 Compositions of Rubber Vulcanizates Prepared fromcis-1,4-Polybutadiene Ingredient Amount (phr) cis-1,4-Polybutadiene 80sample Polyisoprene 20 HAF Carbon black 50 Oil 10 Wax 2 Antioxidant 1Zinc oxide 2.5 Stearic acid 2 Accelerators 1.3 Sulfur 1.5 Total 170.3

The Mooney viscosity (ML₁₊₄) of the uncured rubber compound wasdetermined at 130° C. by using an Alpha Technologies Mooney viscometerwith a large rotor, a one-minute warm-up time, and a four-minute runningtime. The tensile mechanical properties (modulus, T_(b), and E_(b)) ofthe vulcanizates were measured by using the standard procedure describedin ASTM-D412. The hysteresis data (tans) and the Payne effect data (ΔG′)of the vulcanizates were obtained from a dynamic strain-sweepexperiment, which was conducted at 50° C. and 15 Hz with strain sweepingfrom 0.1% to 20%. ΔG′ is the difference between G′ at 0.1% strain and G′at 20% strain. The physical properties of the vulcanizates aresummarized in Table 4. In FIG. 2, the tans data are plotted against thecompound Mooney viscosities.

TABLE 4 Physical Properties of Rubber Vulcanizates Prepared fromcis-1,4- Polybutadiene Example No. Example Example Example 13 Example 1411 12 (comparative) (comparative) Polymer used Example 3 Example 4Example 7 Example 8 Polymer type unmodified unmodified TMSSPhImineTMSSPyImine modified modified Compound ML₁₊₄ 50.5 65.4 55.4 58.0 at 130°C. 300% modulus at 7.54 7.89 7.28 7.48 23° C. (MPa) T_(b) at 23° C. 12.514.8 14.0 15.5 (MPa) E_(b) at 23° C. (%) 419 456 454 484 tanδ at 50° C.,3% 0.145 0.133 0.115 0.117 strain ΔG′ (MPa) 2.51 2.36 1.26 1.40

As can be seen in Table 4 and FIG. 2, at the same compound Mooneyviscosity, the cis-1,4-polybutadiene samples modified with TMMSPhImineor TMMSPyImine give significantly lower tans than the unmodifiedpolymer, indicating that the modification of cis-1,4-polybutadiene withTMMSPhImine or TMMSPyImine reduces hysteresis. At the same compoundMooney viscosity, the cis-1,4-polybutadiene samples modified withTMMSPhImine or TMMSPyImine also give lower ΔG′ than the unmodifiedpolymer, indicating that the Payne effect has been reduced due to thestronger interaction between the modified polymer and carbon black.

Examples 15-18 Compounding Evaluation of cis-1,4-Polybutadiene Modifiedwith trans-N-Benzylideneaniline (PhImine) andtrans-N-(2-Pyridylmethylidene)aniline (PyImine) vs. Unmodifiedcis-1,4-Polybutadiene

The cis-1,4-polybutadiene samples produced in Examples 5, 6, 9, and 10were evaluated in a rubber compound filled with carbon black. Thecompositions of the vulcanizates are presented in Table 3. The physicaltesting conditions for the vulcanizates are the same as those employedfor Examples 11-14. The physical properties of the vulcanizates aresummarized in Table 5. In FIG. 3, the tans data are plotted against thecompound Mooney viscosities.

TABLE 5 Physical Properties of Rubber Vulcanizates Prepared fromcis-1,4- Polybutadiene Example No. Example Example Example 17 Example 1815 16 (comparative) (comparative) Polymer used Example 5 Example 6Example 9 Example 10 (comparative) (comparative) Polymer type unmodifiedunmodified PhImine PyImine modified modified Compound ML₁₊₄ 48.5 69.951.4 45.6 at 130° C. 300% modulus at 7.50 8.50 7.27 7.35 23° C. (MPa)T_(b) at 23° C. (MPa) 13.4 14.6 13.2 13.9 E_(b) at 23° C. (%) 454 441465 474 tanδ at 50° C., 3% 0.139 0.118 0.134 0.137 strain ΔG′ (MPa) 2.712.41 2.56 3.10

As can be seen in Table 5 and FIG. 3, at the same compound Mooneyviscosity, the cis-1,4-polybutadiene samples modified with PhImine orPyImine provide essentially no reduction or only marginal reduction inhysteresis and the Payne effect as compared to the unmodified polymer.

Various modifications and alterations that do not depart from the scopeand spirit of this invention will become apparent to those skilled inthe art. This invention is not to be duly limited to the illustrativeembodiments set forth herein.

What is claimed is:
 1. A method for preparing a functionalized polymer,the method comprising the steps of: (i) polymerizing monomer to form areactive polymer, and (ii) reacting the reactive polymer with an iminecompound containing a protected thiol group.
 2. The method of claim 1,where the imine compound containing a protected thiol group is definedby the formula I:

where R¹ is a hydrogen atom or a monovalent organic group, R² is a bondor a divalent organic group, R³ is a monovalent organic group, and R⁴ isa hydrolyzable group, or where R¹ and R² join to form a trivalentorganic group, or where R¹ and R³ join to form a divalent organic group.3. The method of claim 2, where R⁴ is a silyl group.
 4. The method ofclaim 3, where the silyl group is selected from trihydrocarbylsilyl,dihydrocarbylhydrosilyl, and hydrocarbyldihydrosilyl groups.
 5. Themethod of claim 2, where R⁴ is a silyl group selected fromtrihydrocarbylsilyl, dihydrocarbylhydrosilyl, andhydrocarbyldihydrosilyl groups.
 6. The method of claim 1, where theimine compound containing a protected thiol group is defined by theformula II:

where R⁴ is a hydrolyzable group, R⁵ and R⁶ are each independently ahydrogen atom or a monovalent organic group, and R² is a bond or adivalent organic group, or where R⁵ and R⁶ join to form a divalentorganic group, or where R² and R⁵ join to form a trivalent organicgroup.
 7. The method of claim 1, where the imine compound containing aprotected thiol group is defined by the formula III:

where R³ is a monovalent organic group, R⁴ is a hydrolyzable group, andR⁷ is a trivalent organic group.
 8. The method of claim 1, where theimine compound containing a protected thiol group is defined by theformula IV:

where R² is a bond or a divalent organic group, R⁴ is a hydrolyzablegroup, and R⁸ is a divalent organic group.
 9. The method of claim 1,where the imine compound containing a protected thiol group is definedby the formula V:

where R² is a bond or a divalent organic group, R⁴ is a hydrolyzablegroup, and R¹⁰ is a divalent organic group.
 10. The method of claim 1,where the imine compound containing a protected thiol group is definedby the formula VI:

where R¹ is a hydrogen atom or a monovalent organic group, R² is a bondor a divalent organic group, R³ is a monovalent organic group, and eachR⁹ is individually a hydrogen atom or a monovalent organic group, orwhere R¹ and R² join to form a trivalent organic group, or where R¹ andR³ join to form a divalent organic group.
 11. The method of claim 1,where the imine compound containing a protected thiol group is definedby the formula VII:

where R² is a bond or a divalent organic group, R⁵ and R⁶ are eachindependently a hydrogen atom or a monovalent organic group, and each R⁹is individually a hydrogen atom or a monovalent organic group, or whereR⁵ and R⁶ join to form a divalent organic group, or where R² and R⁵ jointo form a trivalent organic group.
 12. The method of claim 1, where theimine compound containing a protected thiol group is defined by theformula VIII:

where R³ is a monovalent organic group, R⁷ is a trivalent organic group,and each R⁹ is individually a hydrogen atom or a monovalent organicgroup.
 13. The method of claim 1, where the imine compound containing aprotected thiol group is defined by the formula IX:

where R² is a bond or a divalent organic group, R⁸ is a divalent organicgroup, and each R⁹ is individually a hydrogen atom or a monovalentorganic group.
 14. The method of claim 1, where the imine compoundcontaining a protected thiol group is defined by the formula X:

where R² is a bond or a divalent organic group, each R⁹ is individuallya hydrogen atom or a monovalent organic group, and R¹⁰ is a divalentorganic group.
 15. The method of claim 1, where the imine compoundcontaining a protected thiol group is anN-(silylthiohydrocarbylidene)hydrocarbylamine,N-hydrocarbylidene(silylthiohydrocarbyl)amine,N-(silylthiocyclohydrocarbylidene)hydrocarbylamine, orN-cyclohydrocarbylidene(silylthiohydrocarbyl)amine.
 16. The method ofclaim 15, where the imine compound containing a protected thiol group isan N-(silylthiohydrocarbylidene)hydrocarbylamine selected from the groupconsisting of N-[α-(silylthioaryl)hydrocarbylidene]arylamine,N-(silylthioalkylidene)alkylamine,N-[α-(silylthioaryl)hydrocarbylidene]alkylamine, andN-(silylthioalkylidene)arylamine.
 17. The method of claim 15, where theimine compound containing a protected thiol group is anN-hydrocarbylidene(silylthiohydrocarbyl)amine selected from the groupconsisting of N-(α-arylhydrocarbylidene)(silylthioaryl)amine,N-alkylidene(silylthioalkyl)amine,N-(α-arylhydrocarbylidene)(silylthioalkyl)amine, andN-alkylidene(silylthioaryl)amine.
 18. The method of claim 15, where theimine compound containing a protected thiol group is anN-(silylthiocyclohydrocarbylidene)hydrocarbylamine selected from thegroup consisting of N-(silylthiocyclohydrocarbylidene)alkylamine, andN-(silylthiocyclohydrocarbylidene) arylamine.
 19. The method of claim15, where the imine compound containing a protected thiol group is anN-cyclohydrocarbylidene(silylthiohydrocarbyl)amine selected from thegroup consisting of N-cyclohydrocarbylidene(silylthioalkyl)amine, andN-cyclohydrocarbylidene(silylthioaryl)amine.
 20. The method of claim 1,where the monomer includes conjugated diene monomer.
 21. The method ofclaim 20, where said step of polymerizing employs a coordinationcatalyst.
 22. The method of claim 21, where the coordination catalyst isa lanthanide-based catalyst.
 23. The method of claim 22, where thelanthanide-based catalyst includes (a) a lanthanide-containing compound,(b) an alkylating agent, and (c) a halogen source.
 24. The method ofclaim 23, where the alkylating agent includes an aluminoxane and anorganoaluminum compound represented by the formula AlR_(n)X_(3-n), whereeach R, which may be the same or different, is a monovalent organicgroup that is attached to the aluminum atom via a carbon atom, whereeach X, which may be the same or different, is a hydrogen atom, ahalogen atom, a carboxylate group, an alkoxide group, or an aryloxidegroup, and where n is an integer of 1 to
 3. 25. The method of claim 22,where said step of polymerizing monomer takes place within apolymerization mixture including less than 20% by weight of organicsolvent.
 26. The method of claim 20, where said step of polymerizingemploys an anionic initiator.
 27. The method of claim 26, where theanionic initiator is an organolithium compound.
 28. A method forpreparing a functionalized polymer, the method comprising the steps of:(i) polymerizing conjugated diene monomer, and optionally monomercopolymerizable therewith, to form a polymer having a reactive chainend; and (ii) reacting the reactive chain end of the polymer with animine compound containing a protected thiol group.
 29. The method ofclaim 28, where said step of polymerizing employs a coordinationcatalyst or an anionic initiator.
 30. A functionalized polymer preparedby the steps of: (i) polymerizing conjugated diene monomer, andoptionally monomer copolymerizable therewith, to form a polymer having areactive chain end; and (ii) reacting the reactive chain end of thepolymer with an imine compound containing a protected thiol group.
 31. Atire component prepared by employing the functionalized polymer of claim30.
 32. A vulcanizable composition comprising: the functionalizedpolymer of claim 30, a filler, and a curative.